Re: [PATCH] megaraid_sas : Modify return value of megasas_issue_blocked_cmd() and wait_and_poll() to consider command status returned by firmware

[Tomas Henzl <thenzl@redhat.com>]

On 05/06/2015 03:31 PM, Sumit.Saxena@avagotech.com wrote:
> This patch is rebased on top of recently sent 18 patches(submitted by me) for megaraid_sas driver.
> 
> Change the return value of wait_and_poll() and megsas_issue_blocked_cmd() based on MFI_STAT returned by firmware for that command. Earlier driver always
> send return type based on command completion (but never check MFI_STAT_OK for that command), so even if command is failed by firmware still driver will
> return SUCCESS status from these functions wait_and_poll() and megsas_issue_blocked_cmd() and if caller of these functions does not check command status
> (MFI_STAT), then it may endup using invalid data returned in DMA buffers(one of the example is megasas_ld_list_query DCMD). Best thing to avoid this type
> of issue is do error handling and set proper return type from caller function wait_and_poll() and megsas_issue_blocked_cmd().
> 
> The change proposed in this patch will fix the regression introduced in patch- "90dc9d9 megaraid_sas : MFI MPT linked list corruption fix" inside function
> megasas_ld_list_query().
> Prior to this MFI MPT linked list corruption fix patch, megasas_ld_list_query() function used to check DCMD status(returned by firmware) but with
> this linked list corruption fix patch, DCMD status will not be checked inside function megasas_ld_list_query() and introduced this issue of wrong data
> being used by function megasas_ld_list_query().
> 
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
> Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
This patch fixes an issue spotted on my test system.
Thanks for posting.

Reviewed-by: Tomas Henzl <thenzl@redhat.com>

Tomas