RE: [PATCH 07/10] aacraid: Fix AIF triggered IOP_RESET

[Raghava Aditya Renukunta <RaghavaAditya.Renukunta@pmcs.com>]

Hello Johannes,

> -----Original Message-----
> From: Johannes Thumshirn [mailto:jthumshirn@suse.de]
> Sent: Wednesday, December 2, 2015 2:01 AM
> To: Raghava Aditya Renukunta; JBottomley@Parallels.com; linux-
> scsi@vger.kernel.org
> Cc: Mahesh Rajashekhara; Murthy Bhat; Santosh Akula; Gana Sridaran;
> aacraid@pmc-sierra.com; Rich Bono
> Subject: Re: [PATCH 07/10] aacraid: Fix AIF triggered IOP_RESET
> 
> Hi Raghava,
> 
> On Tue, 2015-12-01 at 04:39 -0800, Raghava Aditya Renukunta wrote:
> > From: Raghava Aditya Renukunta <raghavaaditya.renukunta@pmcs.com>
> >
> > while driver removal is in progress or PCI shutdown is invoked, driver
> > kills AIF aacraid thread, but IOCTL requests from the management tools
> > re-start AIF thread leading to IOP_RESET.
> >
> > Fixed by setting adapter_shutdown flag when PCI shutdown is invoked.
> >
> > Signed-off-by: Raghava Aditya Renukunta
> > <raghavaaditya.renukunta@pmcs.com>
> > ---
> >  drivers/scsi/aacraid/linit.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/scsi/aacraid/linit.c
> > b/drivers/scsi/aacraid/linit.c index 6912efd..3a4dbe7 100644
> > --- a/drivers/scsi/aacraid/linit.c
> > +++ b/drivers/scsi/aacraid/linit.c
> > @@ -1454,6 +1454,7 @@ static int aac_suspend(struct pci_dev *pdev,
> > pm_message_t state)
> >  	struct aac_dev *aac = (struct aac_dev *)shost->hostdata;
> >
> >  	scsi_block_requests(shost);
> > +	aac->adapter_shutdown = 1;
> >  	aac_send_shutdown(aac);
> >
> >  	aac_release_resources(aac);
> 
> I don't quite undestand that, the following is from aac_send_shutdown():
> 
> 
> 229         /* FIB should be freed only after getting the response from the F/W
> */
> 230         if (status != -ERESTARTSYS)
> 231                 aac_fib_free(fibctx);
> 232         dev->adapter_shutdown = 1;
> 233         if ((dev->pdev->device == PMC_DEVICE_S7 ||
> 234              dev->pdev->device == PMC_DEVICE_S8 ||
> 
> 
> 
> in line 232 you're already setting the adapter shutdown flag, why do you
> need to pre-set it before calling aac_send_shutdown()?

Originally the problem was that dev->adapter_shutdown was set after the
Shutdown command was sent to the controller, leading to a race
condition  If after the controller was shut down and before
 dev->adapter_shutdown  was set , the driver received  a AIF
 command from management tool , it  would still be sent to the 
controller in aac_cfg_ioctl() leading to a  IOP_RESET.

A fix would  be to set dev->adapter_shutdown at the very 
beginning of aac_send_shutdown().

> 
> Thanks,
> 	Johannes

Thank you,
	Raghava Aditya