On 10/08/2015 06:54 PM, Vitaly Kuznetsov wrote:
> Some host adapters (e.g. Hyper-V storvsc) are known for not respecting the
> SPC-2/3/4 requirement for 'INQUIRY data (see table ...) shall contain at
> least 36 bytes'. As a result we get tons on 'scsi 0:7:1:1: scsi scan:
> INQUIRY result too short (5), using 36' messages on console. This can be
> problematic for slow consoles. Introduce short_inquiry flag in struct
> Scsi_Host to print the message once per host.
> 
> Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
> ---
> Changes since v2:
> - This is a successor of previously sent (and still not merged) "scsi:
>   introduce short_inquiry flag for broken host adapters" patch. I'm not
>   particularly sure which solution is better but I'm leaning towards this
>   one as it doesn't require changes to adapter drivers.
> ---
>  drivers/scsi/scsi_scan.c | 9 ++++++---
>  include/scsi/scsi_host.h | 3 +++
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index f9f3f82..cd347e4 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -701,9 +701,12 @@ static int scsi_probe_lun(struct scsi_device *sdev, 
> unsigned char *inq_result,
>        * strings.
>        */
>       if (sdev->inquiry_len < 36) {
> -             sdev_printk(KERN_INFO, sdev,
> -                         "scsi scan: INQUIRY result too short (%d),"
> -                         " using 36\n", sdev->inquiry_len);
> +             if (!sdev->host->short_inquiry) {
> +                     shost_printk(KERN_INFO, sdev->host,
> +                                 "scsi scan: INQUIRY result too short (%d),"
> +                                 " using 36\n", sdev->inquiry_len);
> +                     sdev->host->short_inquiry = 1;
> +             }
>               sdev->inquiry_len = 36;
>       }
>  
At least you need to check if you've received any valid data here;
'INQUIRY result too short' is also a common error if the interrupt
is hosed when trying to access the device.
So please check for 'inquiry_len > 4' before setting 'short_inquiry'.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                            zSeries & Storage
h...@suse.de                                   +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to