Hello Johannes,
> -----Original Message-----
> From: Johannes Thumshirn [mailto:[email protected]]
> Sent: Wednesday, April 27, 2016 2:30 AM
> To: Raghava Aditya Renukunta
> Cc: [email protected]; [email protected];
> [email protected]; [email protected]; Gana Sridaran; Scott
> Benesh; Vishal Jose Mannanal
> Subject: Re: [PATCH 09/10] aacraid: Fix for KDUMP driver hang
>
> EXTERNAL EMAIL
>
>
> On Mon, Apr 25, 2016 at 11:32:37PM -0700, Raghava Aditya Renukunta wrote:
> > When KDUMP is triggered the driver first talks to the firmware in INTX
> > mode, but the adapter firmware is still in MSIX mode. Therefore the first
> > driver command hangs since the driver is waiting for an INTX response and
> > firmware gives a MSIX response. If when the OS is installed on a RAID
> > drive created by the adapter KDUMP will hang since the driver does not
> > receive a response in sync mode.
> >
> > Fixed by: Change the firmware to INTX mode if it is in MSIX mode before
> > sending the first sync command.
> > Cc: [email protected]
> >
> > Signed-off-by: Raghava Aditya Renukunta
> <[email protected]>
> > ---
> > drivers/scsi/aacraid/aacraid.h | 1 +
> > drivers/scsi/aacraid/comminit.c | 24 ++++++++++++++++++++++++
> > 2 files changed, 25 insertions(+)
> >
> > diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
> > index b70f3eb..0ba8f61 100644
> > --- a/drivers/scsi/aacraid/aacraid.h
> > +++ b/drivers/scsi/aacraid/aacraid.h
> > @@ -29,6 +29,7 @@ enum {
> > #define AAC_INT_MODE_MSI (1<<1)
> > #define AAC_INT_MODE_AIF (1<<2)
> > #define AAC_INT_MODE_SYNC (1<<3)
> > +#define AAC_INT_MODE_MSIX (1<<16)
> >
> > #define AAC_INT_ENABLE_TYPE1_INTX 0xfffffffb
> > #define AAC_INT_ENABLE_TYPE1_MSIX 0xfffffffa
> > diff --git a/drivers/scsi/aacraid/comminit.c
> b/drivers/scsi/aacraid/comminit.c
> > index 50d521a..341ea32 100644
> > --- a/drivers/scsi/aacraid/comminit.c
> > +++ b/drivers/scsi/aacraid/comminit.c
> > @@ -37,6 +37,7 @@
> > #include <linux/spinlock.h>
> > #include <linux/slab.h>
> > #include <linux/blkdev.h>
> > +#include <linux/delay.h>
> > #include <linux/completion.h>
> > #include <linux/mm.h>
> > #include <scsi/scsi_host.h>
> > @@ -47,6 +48,20 @@ struct aac_common aac_config = {
> > .irq_mod = 1
> > };
> >
> > +static inline int aac_is_msix_mode(struct aac_dev *dev)
> > +{
> > + u32 status;
> > +
> > + status = src_readl(dev, MUnit.OMR);
> > + return (status & AAC_INT_MODE_MSIX);
> > +}
> > +
> > +static inline void aac_change_to_intx(struct aac_dev *dev)
> > +{
> > + aac_src_access_devreg(dev, AAC_DISABLE_MSIX);
> > + aac_src_access_devreg(dev, AAC_ENABLE_INTX);
>
> I don't know your adpater firmware, but isn't it possible to loose interrupts
> this way or do they get queued?
The firmware queues interrupts messages in its own buffers, and the driver sends
a command to retrieve those messages once the driver gets initialized.
The code that sends the command once the driver is initialized is in the patch
7 of this
Series.
Hope that clarifies your doubt.
Regards,
Raghava Aditya
> > +}
> > +
> > static int aac_alloc_comm(struct aac_dev *dev, void **commaddr,
> unsigned long commsize, unsigned long commalign)
> > {
> > unsigned char *base;
> > @@ -414,6 +429,15 @@ struct aac_dev *aac_init_adapter(struct aac_dev
> *dev)
> > dev->comm_interface = AAC_COMM_PRODUCER;
> > dev->raw_io_interface = dev->raw_io_64 = 0;
> >
> > +
> > + /*
> > + * Enable INTX mode, if not done already Enabled
> > + */
> > + if (aac_is_msix_mode(dev)) {
> > + aac_change_to_intx(dev);
> > + dev_info(&dev->pdev->dev, "Changed firmware to INTX mode");
> > + }
> > +
> > if ((!aac_adapter_sync_cmd(dev, GET_ADAPTER_PROPERTIES,
> > 0, 0, 0, 0, 0, 0,
> > status+0, status+1, status+2, status+3, NULL)) &&
> >
> > --
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>
> --
> Johannes Thumshirn Storage
> [email protected] +49 911 74053 689
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