Re: [PATCH v3 4/8] megaraid_sas: Send SYNCHRONIZE_CACHE for non-raid to firmware

[Hannes Reinecke <hare@suse.de>]

On 10/21/2016 03:33 PM, Kashyap Desai wrote:
> Commit- " 02b01e0 [SCSI] megaraid_sas: return sync cache call with success"
> added the code in driver to return SYNCHRONIZE_CACHE without sending it to
> firmware back in 2007. Earlier MR was mainly for Virtual Disk,
> so same code continue for JBOD as well whenever JBOD support was added and it introduced bug that
> SYNCHRONIZE_CACHE is not passed to FW for JBOD (non Raid disk).
>
> But our recent analysis indicates that, From Day-1 MR Firmware always
> expect Driver to forward SYNCHRONIZE_CACHE for JBOD (non Raid disk) to the
> Firmware.
> We have fixed this as part of this patch.
>
> CC: stable@vger.kernel.org
> Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
> ---
>  drivers/scsi/megaraid/megaraid_sas_base.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
> index ba57be6..c98d4f9 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
> @@ -1700,16 +1700,13 @@ megasas_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
>  		goto out_done;
>  	}
>
> -	switch (scmd->cmnd[0]) {
> -	case SYNCHRONIZE_CACHE:
> -		/*
> -		 * FW takes care of flush cache on its own
> -		 * No need to send it down
> -		 */
> +	/*
> +	 * FW takes care of flush cache on its own for Virtual Disk.
> +	 * No need to send it down for VD. For JBOD send SYNCHRONIZE_CACHE to FW.
> +	 */
> +	if ((scmd->cmnd[0] == SYNCHRONIZE_CACHE) && MEGASAS_IS_LOGICAL(scmd)) {
>  		scmd->result = DID_OK << 16;
>  		goto out_done;
> -	default:
> -		break;
>  	}
>
>  	return instance->instancet->build_and_issue_cmd(instance, scmd);
>
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
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