On Wed, 2016-08-10 at 22:40 -0400, Martin K. Petersen wrote:
> >>>>> "Oliver" == Oliver Neukum <oneukum@xxxxxxxx> writes:
>
> Oliver> Some SATA to USB bridges fail to cooperate with some drives
> Oliver> resulting in no cache being present being reported to the
> Oliver> host. That causes the host to skip sending a command to
> Oliver> synchronize caches. That causes data loss when the drive is
> Oliver> powered down.
>
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index a6c346d..392d166 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -179,6 +179,7 @@ struct scsi_device {
> unsigned try_rc_10_first:1; /* Try READ_CAPACACITY_10 first */
> unsigned is_visible:1; /* is the device visible in sysfs */
> unsigned wce_default_on:1; /* Cache is ON by default */
> + unsigned always_sync:1; /* synchronize cache in every case*/
> unsigned no_dif:1; /* T10 PI (DIF) should be disabled */
> unsigned broken_fua:1; /* Don't set FUA bit */
> unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */
>
> I must be missing something. How is always_sync different from just
> setting wce_default_on?
Hi,
wce_default_on controls the default if the device provides no
indication. The problem here is that the indication the device
provides must be overridden, as they are false.
Regards
Oliver
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