Re: [PATCH v1 9/9] PCI/portdrv: Remove "pcie_hp=nomsi" kernel parameter

[Rafael J. Wysocki]

On Wednesday, March 7, 2018 7:14:13 AM CET Bjorn Helgaas wrote:
> From: Bjorn Helgaas 
> 
> 7570a333d8b0 ("PCI: Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp
> driver") added the "pcie_hp=nomsi" kernel parameter to work around this
> error on shutdown:
> 
>   irq 16: nobody cared (try booting with the "irqpoll" option)
>   Pid: 1081, comm: reboot Not tainted 3.2.0 #1
>   ...
>   Disabling IRQ #16
> 
> This happened on an unspecified system (possibly involving the Integrated
> Device Technology, Inc. Device 807f bridge) where "an un-wanted interrupt
> is generated when PCI driver switches from MSI/MSI-X to INTx while shutting
> down the device."
> 
> The implication was that the device was buggy, but it is normal for a
> device to use INTx after MSI/MSI-X have been disabled.  The only problem
> was that the driver was still attached and it wasn't prepared for INTx
> interrupts.  Prarit Bhargava fixed this issue with fda78d7a0ead ("PCI/MSI:
> Stop disabling MSI/MSI-X in pci_device_shutdown()").
> 
> There is no automated way to set this parameter, so it's not very useful
> for distributions or end users.  It's really only useful for debugging, and
> we have "pci=nomsi" for that purpose.
> 
> Revert 7570a333d8b0 to remove the "pcie_hp=nomsi" parameter.
> 
> Signed-off-by: Bjorn Helgaas 
> CC: MUNEDA Takahiro 
> CC: Kenji Kaneshige 
> CC: Prarit Bhargava 
> ---
>  Documentation/admin-guide/kernel-parameters.txt |4 
>  drivers/pci/pcie/portdrv.h  |   12 
>  drivers/pci/pcie/portdrv_core.c |   20 +++-
>  3 files changed, 3 insertions(+), 33 deletions(-)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt 
> b/Documentation/admin-guide/kernel-parameters.txt
> index 1d1d53f85ddd..761749562165 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -3130,10 +3130,6 @@
>   force   Enable ASPM even on devices that claim not to support 
> it.
>   WARNING: Forcing ASPM on may cause system lockups.
>  
> - pcie_hp=[PCIE] PCI Express Hotplug driver options:
> - nomsi   Do not use MSI for PCI Express Native Hotplug (this
> - makes all PCIe ports use INTx for hotplug services).
> -
>   pcie_ports= [PCIE] PCIe ports handling:
>   autoAsk the BIOS whether or not to use native PCIe services
>   associated with PCIe ports (PME, hot-plug, AER).  Use
> diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
> index 2c19cf9ffea2..87a87cb9f42d 100644
> --- a/drivers/pci/pcie/portdrv.h
> +++ b/drivers/pci/pcie/portdrv.h
> @@ -34,18 +34,6 @@ void pcie_port_bus_unregister(void);
>  
>  struct pci_dev;
>  
> -#ifdef CONFIG_HOTPLUG_PCI_PCIE
> -extern bool pciehp_msi_disabled;
> -
> -static inline bool pciehp_no_msi(void)
> -{
> - return pciehp_msi_disabled;
> -}
> -
> -#else  /* !CONFIG_HOTPLUG_PCI_PCIE */
> -static inline bool pciehp_no_msi(void) { return false; }
> -#endif /* !CONFIG_HOTPLUG_PCI_PCIE */
> -
>  #ifdef CONFIG_PCIE_PME
>  extern bool pcie_pme_msi_disabled;
>  
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index 29210e9bfbd3..bf9c5c885957 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -21,17 +21,6 @@
>  #include "../pci.h"
>  #include "portdrv.h"
>  
> -bool pciehp_msi_disabled;
> -
> -static int __init pciehp_setup(char *str)
> -{
> - if (!strncmp(str, "nomsi", 5))
> - pciehp_msi_disabled = true;
> -
> - return 1;
> -}
> -__setup("pcie_hp=", pciehp_setup);
> -
>  /**
>   * release_pcie_device - free PCI Express port service device structure
>   * @dev: Port service device to release
> @@ -169,16 +158,13 @@ static int pcie_init_service_irqs(struct pci_dev *dev, 
> int *irqs, int mask)
>   irqs[i] = -1;
>  
>   /*
> -  * If we support PME or hotplug, but we can't use MSI/MSI-X for
> -  * them, we have to fall back to INTx or other interrupts, e.g., a
> -  * system shared interrupt.
> +  * If we support PME but can't use MSI/MSI-X for it, we have to
> +  * fall back to INTx or other interrupts, e.g., a system shared
> +  * interrupt.
>*/
>   if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
>   goto legacy_irq;
>  
> - if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
> - goto legacy_irq;
> -
>   /* Try to use MSI-X or MSI if supported */
>   if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
>   return 0;
> 
> 

Reviewed-by: Rafael J. Wysocki 

Re: [PATCH v1 9/9] PCI/portdrv: Remove "pcie_hp=nomsi" kernel parameter

[Rafael J. Wysocki]

On Wednesday, March 7, 2018 7:14:13 AM CET Bjorn Helgaas wrote:
> From: Bjorn Helgaas 
> 
> 7570a333d8b0 ("PCI: Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp
> driver") added the "pcie_hp=nomsi" kernel parameter to work around this
> error on shutdown:
> 
>   irq 16: nobody cared (try booting with the "irqpoll" option)
>   Pid: 1081, comm: reboot Not tainted 3.2.0 #1
>   ...
>   Disabling IRQ #16
> 
> This happened on an unspecified system (possibly involving the Integrated
> Device Technology, Inc. Device 807f bridge) where "an un-wanted interrupt
> is generated when PCI driver switches from MSI/MSI-X to INTx while shutting
> down the device."
> 
> The implication was that the device was buggy, but it is normal for a
> device to use INTx after MSI/MSI-X have been disabled.  The only problem
> was that the driver was still attached and it wasn't prepared for INTx
> interrupts.  Prarit Bhargava fixed this issue with fda78d7a0ead ("PCI/MSI:
> Stop disabling MSI/MSI-X in pci_device_shutdown()").
> 
> There is no automated way to set this parameter, so it's not very useful
> for distributions or end users.  It's really only useful for debugging, and
> we have "pci=nomsi" for that purpose.
> 
> Revert 7570a333d8b0 to remove the "pcie_hp=nomsi" parameter.
> 
> Signed-off-by: Bjorn Helgaas 
> CC: MUNEDA Takahiro 
> CC: Kenji Kaneshige 
> CC: Prarit Bhargava 
> ---
>  Documentation/admin-guide/kernel-parameters.txt |4 
>  drivers/pci/pcie/portdrv.h  |   12 
>  drivers/pci/pcie/portdrv_core.c |   20 +++-
>  3 files changed, 3 insertions(+), 33 deletions(-)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt 
> b/Documentation/admin-guide/kernel-parameters.txt
> index 1d1d53f85ddd..761749562165 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -3130,10 +3130,6 @@
>   force   Enable ASPM even on devices that claim not to support 
> it.
>   WARNING: Forcing ASPM on may cause system lockups.
>  
> - pcie_hp=[PCIE] PCI Express Hotplug driver options:
> - nomsi   Do not use MSI for PCI Express Native Hotplug (this
> - makes all PCIe ports use INTx for hotplug services).
> -
>   pcie_ports= [PCIE] PCIe ports handling:
>   autoAsk the BIOS whether or not to use native PCIe services
>   associated with PCIe ports (PME, hot-plug, AER).  Use
> diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
> index 2c19cf9ffea2..87a87cb9f42d 100644
> --- a/drivers/pci/pcie/portdrv.h
> +++ b/drivers/pci/pcie/portdrv.h
> @@ -34,18 +34,6 @@ void pcie_port_bus_unregister(void);
>  
>  struct pci_dev;
>  
> -#ifdef CONFIG_HOTPLUG_PCI_PCIE
> -extern bool pciehp_msi_disabled;
> -
> -static inline bool pciehp_no_msi(void)
> -{
> - return pciehp_msi_disabled;
> -}
> -
> -#else  /* !CONFIG_HOTPLUG_PCI_PCIE */
> -static inline bool pciehp_no_msi(void) { return false; }
> -#endif /* !CONFIG_HOTPLUG_PCI_PCIE */
> -
>  #ifdef CONFIG_PCIE_PME
>  extern bool pcie_pme_msi_disabled;
>  
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index 29210e9bfbd3..bf9c5c885957 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -21,17 +21,6 @@
>  #include "../pci.h"
>  #include "portdrv.h"
>  
> -bool pciehp_msi_disabled;
> -
> -static int __init pciehp_setup(char *str)
> -{
> - if (!strncmp(str, "nomsi", 5))
> - pciehp_msi_disabled = true;
> -
> - return 1;
> -}
> -__setup("pcie_hp=", pciehp_setup);
> -
>  /**
>   * release_pcie_device - free PCI Express port service device structure
>   * @dev: Port service device to release
> @@ -169,16 +158,13 @@ static int pcie_init_service_irqs(struct pci_dev *dev, 
> int *irqs, int mask)
>   irqs[i] = -1;
>  
>   /*
> -  * If we support PME or hotplug, but we can't use MSI/MSI-X for
> -  * them, we have to fall back to INTx or other interrupts, e.g., a
> -  * system shared interrupt.
> +  * If we support PME but can't use MSI/MSI-X for it, we have to
> +  * fall back to INTx or other interrupts, e.g., a system shared
> +  * interrupt.
>*/
>   if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
>   goto legacy_irq;
>  
> - if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
> - goto legacy_irq;
> -
>   /* Try to use MSI-X or MSI if supported */
>   if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
>   return 0;
> 
> 

Reviewed-by: Rafael J. Wysocki 

[PATCH v1 9/9] PCI/portdrv: Remove "pcie_hp=nomsi" kernel parameter

[Bjorn Helgaas]

From: Bjorn Helgaas 

7570a333d8b0 ("PCI: Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp
driver") added the "pcie_hp=nomsi" kernel parameter to work around this
error on shutdown:

  irq 16: nobody cared (try booting with the "irqpoll" option)
  Pid: 1081, comm: reboot Not tainted 3.2.0 #1
  ...
  Disabling IRQ #16

This happened on an unspecified system (possibly involving the Integrated
Device Technology, Inc. Device 807f bridge) where "an un-wanted interrupt
is generated when PCI driver switches from MSI/MSI-X to INTx while shutting
down the device."

The implication was that the device was buggy, but it is normal for a
device to use INTx after MSI/MSI-X have been disabled.  The only problem
was that the driver was still attached and it wasn't prepared for INTx
interrupts.  Prarit Bhargava fixed this issue with fda78d7a0ead ("PCI/MSI:
Stop disabling MSI/MSI-X in pci_device_shutdown()").

There is no automated way to set this parameter, so it's not very useful
for distributions or end users.  It's really only useful for debugging, and
we have "pci=nomsi" for that purpose.

Revert 7570a333d8b0 to remove the "pcie_hp=nomsi" parameter.

Signed-off-by: Bjorn Helgaas 
CC: MUNEDA Takahiro 
CC: Kenji Kaneshige 
CC: Prarit Bhargava 
---
 Documentation/admin-guide/kernel-parameters.txt |4 
 drivers/pci/pcie/portdrv.h  |   12 
 drivers/pci/pcie/portdrv_core.c |   20 +++-
 3 files changed, 3 insertions(+), 33 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt 
b/Documentation/admin-guide/kernel-parameters.txt
index 1d1d53f85ddd..761749562165 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3130,10 +3130,6 @@
force   Enable ASPM even on devices that claim not to support 
it.
WARNING: Forcing ASPM on may cause system lockups.
 
-   pcie_hp=[PCIE] PCI Express Hotplug driver options:
-   nomsi   Do not use MSI for PCI Express Native Hotplug (this
-   makes all PCIe ports use INTx for hotplug services).
-
pcie_ports= [PCIE] PCIe ports handling:
autoAsk the BIOS whether or not to use native PCIe services
associated with PCIe ports (PME, hot-plug, AER).  Use
diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index 2c19cf9ffea2..87a87cb9f42d 100644
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -34,18 +34,6 @@ void pcie_port_bus_unregister(void);
 
 struct pci_dev;
 
-#ifdef CONFIG_HOTPLUG_PCI_PCIE
-extern bool pciehp_msi_disabled;
-
-static inline bool pciehp_no_msi(void)
-{
-   return pciehp_msi_disabled;
-}
-
-#else  /* !CONFIG_HOTPLUG_PCI_PCIE */
-static inline bool pciehp_no_msi(void) { return false; }
-#endif /* !CONFIG_HOTPLUG_PCI_PCIE */
-
 #ifdef CONFIG_PCIE_PME
 extern bool pcie_pme_msi_disabled;
 
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 29210e9bfbd3..bf9c5c885957 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -21,17 +21,6 @@
 #include "../pci.h"
 #include "portdrv.h"
 
-bool pciehp_msi_disabled;
-
-static int __init pciehp_setup(char *str)
-{
-   if (!strncmp(str, "nomsi", 5))
-   pciehp_msi_disabled = true;
-
-   return 1;
-}
-__setup("pcie_hp=", pciehp_setup);
-
 /**
  * release_pcie_device - free PCI Express port service device structure
  * @dev: Port service device to release
@@ -169,16 +158,13 @@ static int pcie_init_service_irqs(struct pci_dev *dev, 
int *irqs, int mask)
irqs[i] = -1;
 
/*
-* If we support PME or hotplug, but we can't use MSI/MSI-X for
-* them, we have to fall back to INTx or other interrupts, e.g., a
-* system shared interrupt.
+* If we support PME but can't use MSI/MSI-X for it, we have to
+* fall back to INTx or other interrupts, e.g., a system shared
+* interrupt.
 */
if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
goto legacy_irq;
 
-   if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
-   goto legacy_irq;
-
/* Try to use MSI-X or MSI if supported */
if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
return 0;

[PATCH v1 9/9] PCI/portdrv: Remove "pcie_hp=nomsi" kernel parameter

[Bjorn Helgaas]

From: Bjorn Helgaas 

7570a333d8b0 ("PCI: Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp
driver") added the "pcie_hp=nomsi" kernel parameter to work around this
error on shutdown:

  irq 16: nobody cared (try booting with the "irqpoll" option)
  Pid: 1081, comm: reboot Not tainted 3.2.0 #1
  ...
  Disabling IRQ #16

This happened on an unspecified system (possibly involving the Integrated
Device Technology, Inc. Device 807f bridge) where "an un-wanted interrupt
is generated when PCI driver switches from MSI/MSI-X to INTx while shutting
down the device."

The implication was that the device was buggy, but it is normal for a
device to use INTx after MSI/MSI-X have been disabled.  The only problem
was that the driver was still attached and it wasn't prepared for INTx
interrupts.  Prarit Bhargava fixed this issue with fda78d7a0ead ("PCI/MSI:
Stop disabling MSI/MSI-X in pci_device_shutdown()").

There is no automated way to set this parameter, so it's not very useful
for distributions or end users.  It's really only useful for debugging, and
we have "pci=nomsi" for that purpose.

Revert 7570a333d8b0 to remove the "pcie_hp=nomsi" parameter.

Signed-off-by: Bjorn Helgaas 
CC: MUNEDA Takahiro 
CC: Kenji Kaneshige 
CC: Prarit Bhargava 
---
 Documentation/admin-guide/kernel-parameters.txt |4 
 drivers/pci/pcie/portdrv.h  |   12 
 drivers/pci/pcie/portdrv_core.c |   20 +++-
 3 files changed, 3 insertions(+), 33 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt 
b/Documentation/admin-guide/kernel-parameters.txt
index 1d1d53f85ddd..761749562165 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3130,10 +3130,6 @@
force   Enable ASPM even on devices that claim not to support 
it.
WARNING: Forcing ASPM on may cause system lockups.
 
-   pcie_hp=[PCIE] PCI Express Hotplug driver options:
-   nomsi   Do not use MSI for PCI Express Native Hotplug (this
-   makes all PCIe ports use INTx for hotplug services).
-
pcie_ports= [PCIE] PCIe ports handling:
autoAsk the BIOS whether or not to use native PCIe services
associated with PCIe ports (PME, hot-plug, AER).  Use
diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index 2c19cf9ffea2..87a87cb9f42d 100644
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -34,18 +34,6 @@ void pcie_port_bus_unregister(void);
 
 struct pci_dev;
 
-#ifdef CONFIG_HOTPLUG_PCI_PCIE
-extern bool pciehp_msi_disabled;
-
-static inline bool pciehp_no_msi(void)
-{
-   return pciehp_msi_disabled;
-}
-
-#else  /* !CONFIG_HOTPLUG_PCI_PCIE */
-static inline bool pciehp_no_msi(void) { return false; }
-#endif /* !CONFIG_HOTPLUG_PCI_PCIE */
-
 #ifdef CONFIG_PCIE_PME
 extern bool pcie_pme_msi_disabled;
 
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 29210e9bfbd3..bf9c5c885957 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -21,17 +21,6 @@
 #include "../pci.h"
 #include "portdrv.h"
 
-bool pciehp_msi_disabled;
-
-static int __init pciehp_setup(char *str)
-{
-   if (!strncmp(str, "nomsi", 5))
-   pciehp_msi_disabled = true;
-
-   return 1;
-}
-__setup("pcie_hp=", pciehp_setup);
-
 /**
  * release_pcie_device - free PCI Express port service device structure
  * @dev: Port service device to release
@@ -169,16 +158,13 @@ static int pcie_init_service_irqs(struct pci_dev *dev, 
int *irqs, int mask)
irqs[i] = -1;
 
/*
-* If we support PME or hotplug, but we can't use MSI/MSI-X for
-* them, we have to fall back to INTx or other interrupts, e.g., a
-* system shared interrupt.
+* If we support PME but can't use MSI/MSI-X for it, we have to
+* fall back to INTx or other interrupts, e.g., a system shared
+* interrupt.
 */
if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
goto legacy_irq;
 
-   if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
-   goto legacy_irq;
-
/* Try to use MSI-X or MSI if supported */
if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
return 0;