Re: [PATCH 15/20] [SCSI] mpt3sas: Return host busy error status to SML when DMA mapping of scatter gather list fails for a SCSI command

[Johannes Thumshirn <jthumshirn@suse.de>]

On Fri, Jun 12, 2015 at 03:12:27PM +0530, Sreekanth Reddy wrote:
> scsi_dma_map API will return a negative value (i.e. -ENOMEM)
> if DMA mapping of sg lists fails and zero if the sg list in the
> SCSI cmd is NULL. But drivers doesn't handled sg list DMA mapping
> failure case properly.
> 
> So, Updated the code to return host busy error status to SCSI MID Layer(SML),
> when DMA mapping of scatter gather list fails for a SCSI command.
> So that SML will retry this SCSI cmd after some time.
> 
> Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
> ---
>  drivers/scsi/mpt3sas/mpt3sas_base.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
> index 267e489..0b26c8d 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_base.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
> @@ -1345,7 +1345,7 @@ _base_build_sg_scmd_ieee(struct MPT3SAS_ADAPTER *ioc,
>  
>  	sg_scmd = scsi_sglist(scmd);
>  	sges_left = scsi_dma_map(scmd);
> -	if (!sges_left) {
> +	if (!sges_left < 0) {
>  		sdev_printk(KERN_ERR, scmd->device,
>  			"pci_map_sg failed: request for %d bytes!\n",
>  			scsi_bufflen(scmd));
> @@ -1414,7 +1414,7 @@ _base_build_sg_scmd_ieee(struct MPT3SAS_ADAPTER *ioc,
>   fill_in_last_segment:
>  
>  	/* fill the last segment */
> -	while (sges_left) {
> +	while (sges_left > 0) {
>  		if (sges_left == 1)
>  			_base_add_sg_single_ieee(sg_local,
>  			    simple_sgl_flags_last, 0, sg_dma_len(sg_scmd),
> -- 
> 2.0.2
> 
> --
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Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

-- 
Johannes Thumshirn                                       Storage
jthumshirn@suse.de                             +49 911 74053 689
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