Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-20 Thread Bjorn Helgaas
On Thu, Sep 13, 2018 at 04:05:54PM +0100, Lorenzo Pieralisi wrote:
> On Wed, Aug 29, 2018 at 11:04:08AM +0800, Jisheng Zhang wrote:
> > When programming inbound/outbound atu, we call usleep_range() after
> > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > can be called in atomic context:
> > 
> > inbound atu programming could be called through
> > pci_epc_write_header()
> >   =>dw_pcie_ep_write_header()
> > =>dw_pcie_prog_inbound_atu()
> > 
> > outbound atu programming could be called through
> > pci_bus_read_config_dword()
> >   =>dw_pcie_rd_conf()
> > =>dw_pcie_prog_outbound_atu()
> > 
> > Fix this issue by calling mdelay() instead.
> > 
> > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
> > Signed-off-by: Jisheng Zhang 
> > Acked-by: Gustavo Pimentel 
> > ---
> 
> Applied to pci/controller-fixes aiming at one of the upcoming -rc*.

I cherry-picked this into for-linus for v4.19.

> > since v2:
> >  - Add Fixes tag
> >  - Add Gustavo's Ack
> > 
> > since v1:
> >  - use mdelay() instead of udelay() to avoid __bad_udelay()
> > 
> >  drivers/pci/controller/dwc/pcie-designware.c | 8 
> >  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
> >  2 files changed, 5 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> > b/drivers/pci/controller/dwc/pcie-designware.c
> > index 778c4f76a884..2153956a0b20 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> > index, int type,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> > index, int bar,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> > b/drivers/pci/controller/dwc/pcie-designware.h
> > index 96126fd8403c..9f1a5e399b70 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -26,8 +26,7 @@
> >  
> >  /* Parameters for the waiting for iATU enabled routine */
> >  #define LINK_WAIT_MAX_IATU_RETRIES 5
> > -#define LINK_WAIT_IATU_MIN 9000
> > -#define LINK_WAIT_IATU_MAX 1
> > +#define LINK_WAIT_IATU 9
> >  
> >  /* Synopsys-specific PCIe configuration registers */
> >  #define PCIE_PORT_LINK_CONTROL 0x710
> > -- 
> > 2.18.0
> > 
> 
> ___
> linux-arm-kernel mailing list
> linux-arm-ker...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-20 Thread Bjorn Helgaas
On Thu, Sep 13, 2018 at 04:05:54PM +0100, Lorenzo Pieralisi wrote:
> On Wed, Aug 29, 2018 at 11:04:08AM +0800, Jisheng Zhang wrote:
> > When programming inbound/outbound atu, we call usleep_range() after
> > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > can be called in atomic context:
> > 
> > inbound atu programming could be called through
> > pci_epc_write_header()
> >   =>dw_pcie_ep_write_header()
> > =>dw_pcie_prog_inbound_atu()
> > 
> > outbound atu programming could be called through
> > pci_bus_read_config_dword()
> >   =>dw_pcie_rd_conf()
> > =>dw_pcie_prog_outbound_atu()
> > 
> > Fix this issue by calling mdelay() instead.
> > 
> > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
> > Signed-off-by: Jisheng Zhang 
> > Acked-by: Gustavo Pimentel 
> > ---
> 
> Applied to pci/controller-fixes aiming at one of the upcoming -rc*.

I cherry-picked this into for-linus for v4.19.

> > since v2:
> >  - Add Fixes tag
> >  - Add Gustavo's Ack
> > 
> > since v1:
> >  - use mdelay() instead of udelay() to avoid __bad_udelay()
> > 
> >  drivers/pci/controller/dwc/pcie-designware.c | 8 
> >  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
> >  2 files changed, 5 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> > b/drivers/pci/controller/dwc/pcie-designware.c
> > index 778c4f76a884..2153956a0b20 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> > index, int type,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> > index, int bar,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> > b/drivers/pci/controller/dwc/pcie-designware.h
> > index 96126fd8403c..9f1a5e399b70 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -26,8 +26,7 @@
> >  
> >  /* Parameters for the waiting for iATU enabled routine */
> >  #define LINK_WAIT_MAX_IATU_RETRIES 5
> > -#define LINK_WAIT_IATU_MIN 9000
> > -#define LINK_WAIT_IATU_MAX 1
> > +#define LINK_WAIT_IATU 9
> >  
> >  /* Synopsys-specific PCIe configuration registers */
> >  #define PCIE_PORT_LINK_CONTROL 0x710
> > -- 
> > 2.18.0
> > 
> 
> ___
> linux-arm-kernel mailing list
> linux-arm-ker...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Lorenzo Pieralisi
On Wed, Aug 29, 2018 at 11:04:08AM +0800, Jisheng Zhang wrote:
> When programming inbound/outbound atu, we call usleep_range() after
> each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> can be called in atomic context:
> 
> inbound atu programming could be called through
> pci_epc_write_header()
>   =>dw_pcie_ep_write_header()
> =>dw_pcie_prog_inbound_atu()
> 
> outbound atu programming could be called through
> pci_bus_read_config_dword()
>   =>dw_pcie_rd_conf()
> =>dw_pcie_prog_outbound_atu()
> 
> Fix this issue by calling mdelay() instead.
> 
> Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
> Signed-off-by: Jisheng Zhang 
> Acked-by: Gustavo Pimentel 
> ---

Applied to pci/controller-fixes aiming at one of the upcoming -rc*.

Thanks,
Lorenzo

> since v2:
>  - Add Fixes tag
>  - Add Gustavo's Ack
> 
> since v1:
>  - use mdelay() instead of udelay() to avoid __bad_udelay()
> 
>  drivers/pci/controller/dwc/pcie-designware.c | 8 
>  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
>  2 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> b/drivers/pci/controller/dwc/pcie-designware.c
> index 778c4f76a884..2153956a0b20 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> dw_pcie *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> index, int type,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie 
> *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> index, int bar,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> b/drivers/pci/controller/dwc/pcie-designware.h
> index 96126fd8403c..9f1a5e399b70 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -26,8 +26,7 @@
>  
>  /* Parameters for the waiting for iATU enabled routine */
>  #define LINK_WAIT_MAX_IATU_RETRIES   5
> -#define LINK_WAIT_IATU_MIN   9000
> -#define LINK_WAIT_IATU_MAX   1
> +#define LINK_WAIT_IATU   9
>  
>  /* Synopsys-specific PCIe configuration registers */
>  #define PCIE_PORT_LINK_CONTROL   0x710
> -- 
> 2.18.0
> 


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Lorenzo Pieralisi
On Wed, Aug 29, 2018 at 11:04:08AM +0800, Jisheng Zhang wrote:
> When programming inbound/outbound atu, we call usleep_range() after
> each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> can be called in atomic context:
> 
> inbound atu programming could be called through
> pci_epc_write_header()
>   =>dw_pcie_ep_write_header()
> =>dw_pcie_prog_inbound_atu()
> 
> outbound atu programming could be called through
> pci_bus_read_config_dword()
>   =>dw_pcie_rd_conf()
> =>dw_pcie_prog_outbound_atu()
> 
> Fix this issue by calling mdelay() instead.
> 
> Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
> Signed-off-by: Jisheng Zhang 
> Acked-by: Gustavo Pimentel 
> ---

Applied to pci/controller-fixes aiming at one of the upcoming -rc*.

Thanks,
Lorenzo

> since v2:
>  - Add Fixes tag
>  - Add Gustavo's Ack
> 
> since v1:
>  - use mdelay() instead of udelay() to avoid __bad_udelay()
> 
>  drivers/pci/controller/dwc/pcie-designware.c | 8 
>  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
>  2 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> b/drivers/pci/controller/dwc/pcie-designware.c
> index 778c4f76a884..2153956a0b20 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> dw_pcie *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> index, int type,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie 
> *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> index, int bar,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> b/drivers/pci/controller/dwc/pcie-designware.h
> index 96126fd8403c..9f1a5e399b70 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -26,8 +26,7 @@
>  
>  /* Parameters for the waiting for iATU enabled routine */
>  #define LINK_WAIT_MAX_IATU_RETRIES   5
> -#define LINK_WAIT_IATU_MIN   9000
> -#define LINK_WAIT_IATU_MAX   1
> +#define LINK_WAIT_IATU   9
>  
>  /* Synopsys-specific PCIe configuration registers */
>  #define PCIE_PORT_LINK_CONTROL   0x710
> -- 
> 2.18.0
> 


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Lorenzo Pieralisi
On Thu, Sep 13, 2018 at 06:29:54PM +0800, Jisheng Zhang wrote:
> Hi Lorenzo,
> 
> On Thu, 13 Sep 2018 10:15:34 +0100 Lorenzo Pieralisi wrote:
> 
> > On Mon, Sep 10, 2018 at 04:57:22PM +0800, Jisheng Zhang wrote:
> > > Hi all,
> > > 
> > > On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:
> > >   
> > > > When programming inbound/outbound atu, we call usleep_range() after
> > > > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > > > can be called in atomic context:
> > > > 
> > > > inbound atu programming could be called through
> > > > pci_epc_write_header()  
> > > >   =>dw_pcie_ep_write_header()
> > > > =>dw_pcie_prog_inbound_atu()
> > > > 
> > > > outbound atu programming could be called through
> > > > pci_bus_read_config_dword()  
> > > >   =>dw_pcie_rd_conf()
> > > > =>dw_pcie_prog_outbound_atu()
> > > > 
> > > > Fix this issue by calling mdelay() instead.  
> > > 
> > > Any comments about this patch?
> > > 
> > > Thanks,
> > > Jisheng
> > >   
> > > > 
> > > > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > > > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")  
> > 
> > Can you split it into two patches and repost it please ? It will make
> > everyone's life easier to backport it if there is need, I will apply
> > then.
> 
> IIUC, the purpose of this split is to make the backport to stable easier. If
> so, I realise that the Fixes tags were not enough, we missed:
> 
> Fixes: edd45e396829 ("PCI: dwc: designware: Move _unroll configurations to a
> separate function")
> 
> I'm not sure how to handle this case. From another side, the issue to be
> fixed is the same: call sleep in atomic context in the same driver, is it
> better to use one patch?
> 
> As for stable tree, I could send out separate patches instead. What do you
> think?

OK, I will merge the patch as-is and we will handle the stable backports
when Greg sends the patches out.

Lorenzo


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Lorenzo Pieralisi
On Thu, Sep 13, 2018 at 06:29:54PM +0800, Jisheng Zhang wrote:
> Hi Lorenzo,
> 
> On Thu, 13 Sep 2018 10:15:34 +0100 Lorenzo Pieralisi wrote:
> 
> > On Mon, Sep 10, 2018 at 04:57:22PM +0800, Jisheng Zhang wrote:
> > > Hi all,
> > > 
> > > On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:
> > >   
> > > > When programming inbound/outbound atu, we call usleep_range() after
> > > > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > > > can be called in atomic context:
> > > > 
> > > > inbound atu programming could be called through
> > > > pci_epc_write_header()  
> > > >   =>dw_pcie_ep_write_header()
> > > > =>dw_pcie_prog_inbound_atu()
> > > > 
> > > > outbound atu programming could be called through
> > > > pci_bus_read_config_dword()  
> > > >   =>dw_pcie_rd_conf()
> > > > =>dw_pcie_prog_outbound_atu()
> > > > 
> > > > Fix this issue by calling mdelay() instead.  
> > > 
> > > Any comments about this patch?
> > > 
> > > Thanks,
> > > Jisheng
> > >   
> > > > 
> > > > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > > > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")  
> > 
> > Can you split it into two patches and repost it please ? It will make
> > everyone's life easier to backport it if there is need, I will apply
> > then.
> 
> IIUC, the purpose of this split is to make the backport to stable easier. If
> so, I realise that the Fixes tags were not enough, we missed:
> 
> Fixes: edd45e396829 ("PCI: dwc: designware: Move _unroll configurations to a
> separate function")
> 
> I'm not sure how to handle this case. From another side, the issue to be
> fixed is the same: call sleep in atomic context in the same driver, is it
> better to use one patch?
> 
> As for stable tree, I could send out separate patches instead. What do you
> think?

OK, I will merge the patch as-is and we will handle the stable backports
when Greg sends the patches out.

Lorenzo


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Jisheng Zhang
Hi Lorenzo,

On Thu, 13 Sep 2018 10:15:34 +0100 Lorenzo Pieralisi wrote:

> On Mon, Sep 10, 2018 at 04:57:22PM +0800, Jisheng Zhang wrote:
> > Hi all,
> > 
> > On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:
> >   
> > > When programming inbound/outbound atu, we call usleep_range() after
> > > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > > can be called in atomic context:
> > > 
> > > inbound atu programming could be called through
> > > pci_epc_write_header()  
> > >   =>dw_pcie_ep_write_header()
> > > =>dw_pcie_prog_inbound_atu()
> > > 
> > > outbound atu programming could be called through
> > > pci_bus_read_config_dword()  
> > >   =>dw_pcie_rd_conf()
> > > =>dw_pcie_prog_outbound_atu()
> > > 
> > > Fix this issue by calling mdelay() instead.  
> > 
> > Any comments about this patch?
> > 
> > Thanks,
> > Jisheng
> >   
> > > 
> > > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")  
> 
> Can you split it into two patches and repost it please ? It will make
> everyone's life easier to backport it if there is need, I will apply
> then.

IIUC, the purpose of this split is to make the backport to stable easier. If
so, I realise that the Fixes tags were not enough, we missed:

Fixes: edd45e396829 ("PCI: dwc: designware: Move _unroll configurations to a
separate function")

I'm not sure how to handle this case. From another side, the issue to be
fixed is the same: call sleep in atomic context in the same driver, is it
better to use one patch?

As for stable tree, I could send out separate patches instead. What do you
think?

Thanks,
Jisheng


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Jisheng Zhang
Hi Lorenzo,

On Thu, 13 Sep 2018 10:15:34 +0100 Lorenzo Pieralisi wrote:

> On Mon, Sep 10, 2018 at 04:57:22PM +0800, Jisheng Zhang wrote:
> > Hi all,
> > 
> > On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:
> >   
> > > When programming inbound/outbound atu, we call usleep_range() after
> > > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > > can be called in atomic context:
> > > 
> > > inbound atu programming could be called through
> > > pci_epc_write_header()  
> > >   =>dw_pcie_ep_write_header()
> > > =>dw_pcie_prog_inbound_atu()
> > > 
> > > outbound atu programming could be called through
> > > pci_bus_read_config_dword()  
> > >   =>dw_pcie_rd_conf()
> > > =>dw_pcie_prog_outbound_atu()
> > > 
> > > Fix this issue by calling mdelay() instead.  
> > 
> > Any comments about this patch?
> > 
> > Thanks,
> > Jisheng
> >   
> > > 
> > > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")  
> 
> Can you split it into two patches and repost it please ? It will make
> everyone's life easier to backport it if there is need, I will apply
> then.

IIUC, the purpose of this split is to make the backport to stable easier. If
so, I realise that the Fixes tags were not enough, we missed:

Fixes: edd45e396829 ("PCI: dwc: designware: Move _unroll configurations to a
separate function")

I'm not sure how to handle this case. From another side, the issue to be
fixed is the same: call sleep in atomic context in the same driver, is it
better to use one patch?

As for stable tree, I could send out separate patches instead. What do you
think?

Thanks,
Jisheng


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Lorenzo Pieralisi
On Mon, Sep 10, 2018 at 04:57:22PM +0800, Jisheng Zhang wrote:
> Hi all,
> 
> On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:
> 
> > When programming inbound/outbound atu, we call usleep_range() after
> > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > can be called in atomic context:
> > 
> > inbound atu programming could be called through
> > pci_epc_write_header()
> >   =>dw_pcie_ep_write_header()
> > =>dw_pcie_prog_inbound_atu()  
> > 
> > outbound atu programming could be called through
> > pci_bus_read_config_dword()
> >   =>dw_pcie_rd_conf()
> > =>dw_pcie_prog_outbound_atu()  
> > 
> > Fix this issue by calling mdelay() instead.
> 
> Any comments about this patch?
> 
> Thanks,
> Jisheng
> 
> > 
> > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")

Can you split it into two patches and repost it please ? It will make
everyone's life easier to backport it if there is need, I will apply
then.

Thanks,
Lorenzo

> > Signed-off-by: Jisheng Zhang 
> > Acked-by: Gustavo Pimentel 
> > ---
> > 
> > since v2:
> >  - Add Fixes tag
> >  - Add Gustavo's Ack
> > 
> > since v1:
> >  - use mdelay() instead of udelay() to avoid __bad_udelay()
> > 
> >  drivers/pci/controller/dwc/pcie-designware.c | 8 
> >  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
> >  2 files changed, 5 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> > b/drivers/pci/controller/dwc/pcie-designware.c
> > index 778c4f76a884..2153956a0b20 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> > index, int type,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> > index, int bar,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> > b/drivers/pci/controller/dwc/pcie-designware.h
> > index 96126fd8403c..9f1a5e399b70 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -26,8 +26,7 @@
> >  
> >  /* Parameters for the waiting for iATU enabled routine */
> >  #define LINK_WAIT_MAX_IATU_RETRIES 5
> > -#define LINK_WAIT_IATU_MIN 9000
> > -#define LINK_WAIT_IATU_MAX 1
> > +#define LINK_WAIT_IATU 9
> >  
> >  /* Synopsys-specific PCIe configuration registers */
> >  #define PCIE_PORT_LINK_CONTROL 0x710
> 


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-13 Thread Lorenzo Pieralisi
On Mon, Sep 10, 2018 at 04:57:22PM +0800, Jisheng Zhang wrote:
> Hi all,
> 
> On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:
> 
> > When programming inbound/outbound atu, we call usleep_range() after
> > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> > can be called in atomic context:
> > 
> > inbound atu programming could be called through
> > pci_epc_write_header()
> >   =>dw_pcie_ep_write_header()
> > =>dw_pcie_prog_inbound_atu()  
> > 
> > outbound atu programming could be called through
> > pci_bus_read_config_dword()
> >   =>dw_pcie_rd_conf()
> > =>dw_pcie_prog_outbound_atu()  
> > 
> > Fix this issue by calling mdelay() instead.
> 
> Any comments about this patch?
> 
> Thanks,
> Jisheng
> 
> > 
> > Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> > Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")

Can you split it into two patches and repost it please ? It will make
everyone's life easier to backport it if there is need, I will apply
then.

Thanks,
Lorenzo

> > Signed-off-by: Jisheng Zhang 
> > Acked-by: Gustavo Pimentel 
> > ---
> > 
> > since v2:
> >  - Add Fixes tag
> >  - Add Gustavo's Ack
> > 
> > since v1:
> >  - use mdelay() instead of udelay() to avoid __bad_udelay()
> > 
> >  drivers/pci/controller/dwc/pcie-designware.c | 8 
> >  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
> >  2 files changed, 5 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> > b/drivers/pci/controller/dwc/pcie-designware.c
> > index 778c4f76a884..2153956a0b20 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> > index, int type,
> > if (val & PCIE_ATU_ENABLE)
> > return;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Outbound iATU is not being enabled\n");
> >  }
> > @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct 
> > dw_pcie *pci, int index,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> > index, int bar,
> > if (val & PCIE_ATU_ENABLE)
> > return 0;
> >  
> > -   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> > +   mdelay(LINK_WAIT_IATU);
> > }
> > dev_err(pci->dev, "Inbound iATU is not being enabled\n");
> >  
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> > b/drivers/pci/controller/dwc/pcie-designware.h
> > index 96126fd8403c..9f1a5e399b70 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -26,8 +26,7 @@
> >  
> >  /* Parameters for the waiting for iATU enabled routine */
> >  #define LINK_WAIT_MAX_IATU_RETRIES 5
> > -#define LINK_WAIT_IATU_MIN 9000
> > -#define LINK_WAIT_IATU_MAX 1
> > +#define LINK_WAIT_IATU 9
> >  
> >  /* Synopsys-specific PCIe configuration registers */
> >  #define PCIE_PORT_LINK_CONTROL 0x710
> 


Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-10 Thread Jisheng Zhang
Hi all,

On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:

> When programming inbound/outbound atu, we call usleep_range() after
> each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> can be called in atomic context:
> 
> inbound atu programming could be called through
> pci_epc_write_header()
>   =>dw_pcie_ep_write_header()
> =>dw_pcie_prog_inbound_atu()  
> 
> outbound atu programming could be called through
> pci_bus_read_config_dword()
>   =>dw_pcie_rd_conf()
> =>dw_pcie_prog_outbound_atu()  
> 
> Fix this issue by calling mdelay() instead.

Any comments about this patch?

Thanks,
Jisheng

> 
> Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
> Signed-off-by: Jisheng Zhang 
> Acked-by: Gustavo Pimentel 
> ---
> 
> since v2:
>  - Add Fixes tag
>  - Add Gustavo's Ack
> 
> since v1:
>  - use mdelay() instead of udelay() to avoid __bad_udelay()
> 
>  drivers/pci/controller/dwc/pcie-designware.c | 8 
>  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
>  2 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> b/drivers/pci/controller/dwc/pcie-designware.c
> index 778c4f76a884..2153956a0b20 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> dw_pcie *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> index, int type,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie 
> *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> index, int bar,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> b/drivers/pci/controller/dwc/pcie-designware.h
> index 96126fd8403c..9f1a5e399b70 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -26,8 +26,7 @@
>  
>  /* Parameters for the waiting for iATU enabled routine */
>  #define LINK_WAIT_MAX_IATU_RETRIES   5
> -#define LINK_WAIT_IATU_MIN   9000
> -#define LINK_WAIT_IATU_MAX   1
> +#define LINK_WAIT_IATU   9
>  
>  /* Synopsys-specific PCIe configuration registers */
>  #define PCIE_PORT_LINK_CONTROL   0x710



Re: [PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-09-10 Thread Jisheng Zhang
Hi all,

On Wed, 29 Aug 2018 11:04:08 +0800 Jisheng Zhang wrote:

> When programming inbound/outbound atu, we call usleep_range() after
> each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
> can be called in atomic context:
> 
> inbound atu programming could be called through
> pci_epc_write_header()
>   =>dw_pcie_ep_write_header()
> =>dw_pcie_prog_inbound_atu()  
> 
> outbound atu programming could be called through
> pci_bus_read_config_dword()
>   =>dw_pcie_rd_conf()
> =>dw_pcie_prog_outbound_atu()  
> 
> Fix this issue by calling mdelay() instead.

Any comments about this patch?

Thanks,
Jisheng

> 
> Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
> Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
> Signed-off-by: Jisheng Zhang 
> Acked-by: Gustavo Pimentel 
> ---
> 
> since v2:
>  - Add Fixes tag
>  - Add Gustavo's Ack
> 
> since v1:
>  - use mdelay() instead of udelay() to avoid __bad_udelay()
> 
>  drivers/pci/controller/dwc/pcie-designware.c | 8 
>  drivers/pci/controller/dwc/pcie-designware.h | 3 +--
>  2 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
> b/drivers/pci/controller/dwc/pcie-designware.c
> index 778c4f76a884..2153956a0b20 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct 
> dw_pcie *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
> index, int type,
>   if (val & PCIE_ATU_ENABLE)
>   return;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Outbound iATU is not being enabled\n");
>  }
> @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie 
> *pci, int index,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
> index, int bar,
>   if (val & PCIE_ATU_ENABLE)
>   return 0;
>  
> - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
> + mdelay(LINK_WAIT_IATU);
>   }
>   dev_err(pci->dev, "Inbound iATU is not being enabled\n");
>  
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
> b/drivers/pci/controller/dwc/pcie-designware.h
> index 96126fd8403c..9f1a5e399b70 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -26,8 +26,7 @@
>  
>  /* Parameters for the waiting for iATU enabled routine */
>  #define LINK_WAIT_MAX_IATU_RETRIES   5
> -#define LINK_WAIT_IATU_MIN   9000
> -#define LINK_WAIT_IATU_MAX   1
> +#define LINK_WAIT_IATU   9
>  
>  /* Synopsys-specific PCIe configuration registers */
>  #define PCIE_PORT_LINK_CONTROL   0x710



[PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-08-28 Thread Jisheng Zhang
When programming inbound/outbound atu, we call usleep_range() after
each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
can be called in atomic context:

inbound atu programming could be called through
pci_epc_write_header()
  =>dw_pcie_ep_write_header()
=>dw_pcie_prog_inbound_atu()

outbound atu programming could be called through
pci_bus_read_config_dword()
  =>dw_pcie_rd_conf()
=>dw_pcie_prog_outbound_atu()

Fix this issue by calling mdelay() instead.

Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
Signed-off-by: Jisheng Zhang 
Acked-by: Gustavo Pimentel 
---

since v2:
 - Add Fixes tag
 - Add Gustavo's Ack

since v1:
 - use mdelay() instead of udelay() to avoid __bad_udelay()

 drivers/pci/controller/dwc/pcie-designware.c | 8 
 drivers/pci/controller/dwc/pcie-designware.h | 3 +--
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
b/drivers/pci/controller/dwc/pcie-designware.c
index 778c4f76a884..2153956a0b20 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie 
*pci, int index,
if (val & PCIE_ATU_ENABLE)
return;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Outbound iATU is not being enabled\n");
 }
@@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
index, int type,
if (val & PCIE_ATU_ENABLE)
return;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Outbound iATU is not being enabled\n");
 }
@@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie 
*pci, int index,
if (val & PCIE_ATU_ENABLE)
return 0;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Inbound iATU is not being enabled\n");
 
@@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
index, int bar,
if (val & PCIE_ATU_ENABLE)
return 0;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Inbound iATU is not being enabled\n");
 
diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
b/drivers/pci/controller/dwc/pcie-designware.h
index 96126fd8403c..9f1a5e399b70 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -26,8 +26,7 @@
 
 /* Parameters for the waiting for iATU enabled routine */
 #define LINK_WAIT_MAX_IATU_RETRIES 5
-#define LINK_WAIT_IATU_MIN 9000
-#define LINK_WAIT_IATU_MAX 1
+#define LINK_WAIT_IATU 9
 
 /* Synopsys-specific PCIe configuration registers */
 #define PCIE_PORT_LINK_CONTROL 0x710
-- 
2.18.0



[PATCH v3] PCI: dwc: fix scheduling while atomic issues

2018-08-28 Thread Jisheng Zhang
When programming inbound/outbound atu, we call usleep_range() after
each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
can be called in atomic context:

inbound atu programming could be called through
pci_epc_write_header()
  =>dw_pcie_ep_write_header()
=>dw_pcie_prog_inbound_atu()

outbound atu programming could be called through
pci_bus_read_config_dword()
  =>dw_pcie_rd_conf()
=>dw_pcie_prog_outbound_atu()

Fix this issue by calling mdelay() instead.

Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable")
Signed-off-by: Jisheng Zhang 
Acked-by: Gustavo Pimentel 
---

since v2:
 - Add Fixes tag
 - Add Gustavo's Ack

since v1:
 - use mdelay() instead of udelay() to avoid __bad_udelay()

 drivers/pci/controller/dwc/pcie-designware.c | 8 
 drivers/pci/controller/dwc/pcie-designware.h | 3 +--
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c 
b/drivers/pci/controller/dwc/pcie-designware.c
index 778c4f76a884..2153956a0b20 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie 
*pci, int index,
if (val & PCIE_ATU_ENABLE)
return;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Outbound iATU is not being enabled\n");
 }
@@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int 
index, int type,
if (val & PCIE_ATU_ENABLE)
return;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Outbound iATU is not being enabled\n");
 }
@@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie 
*pci, int index,
if (val & PCIE_ATU_ENABLE)
return 0;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Inbound iATU is not being enabled\n");
 
@@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int 
index, int bar,
if (val & PCIE_ATU_ENABLE)
return 0;
 
-   usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+   mdelay(LINK_WAIT_IATU);
}
dev_err(pci->dev, "Inbound iATU is not being enabled\n");
 
diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
b/drivers/pci/controller/dwc/pcie-designware.h
index 96126fd8403c..9f1a5e399b70 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -26,8 +26,7 @@
 
 /* Parameters for the waiting for iATU enabled routine */
 #define LINK_WAIT_MAX_IATU_RETRIES 5
-#define LINK_WAIT_IATU_MIN 9000
-#define LINK_WAIT_IATU_MAX 1
+#define LINK_WAIT_IATU 9
 
 /* Synopsys-specific PCIe configuration registers */
 #define PCIE_PORT_LINK_CONTROL 0x710
-- 
2.18.0