Re: [PATCH] ata: libata-scsi: fix SYNCHRONIZE CACHE (16) command failure

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 11/7/22 09:47, Shin'ichiro Kawasaki wrote:
> SAT SCSI/ATA Translation specification requires SCSI SYNCHRONIZE CACHE
> (10) and (16) commands both shall be translated to ATA flush command.
> However, libata translates only SYNCHRONIZE CACHE (10). This results in
> SYNCHRONIZE CACHE (16) command failures. To avoid the failure, add
> support for SYNCHRONIZE CACHE (16).

Also mention that SYNCHRONIZE CACHE 16 is mandatory for ZBC drives (see
below).

> 
> This patch conflicts with kernels version 5.4 and older. Conflict
> resolution will be required to back port to them.

The above is not needed.

> 
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Cc: stable@vger.kernel.org # v5.10+

Remove the version number.

> ---
>  drivers/ata/libata-scsi.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index e2ebb0b065e2..61cd4e90e4e7 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -3264,6 +3264,7 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
>  	case REPORT_LUNS:
>  	case REQUEST_SENSE:
>  	case SYNCHRONIZE_CACHE:
> +	case SYNCHRONIZE_CACHE_16:
>  	case REZERO_UNIT:
>  	case SEEK_6:
>  	case SEEK_10:
> @@ -3922,6 +3923,7 @@ static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
>  		return ata_scsi_write_same_xlat;
>  
>  	case SYNCHRONIZE_CACHE:
> +	case SYNCHRONIZE_CACHE_16:
>  		if (ata_try_flush_cache(dev))
>  			return ata_scsi_flush_xlat;
>  		break;
> @@ -4145,6 +4147,7 @@ void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd)
>  	 * turning this into a no-op.
>  	 */
>  	case SYNCHRONIZE_CACHE:
> +	case SYNCHRONIZE_CACHE_16:
>  		fallthrough;
>  
>  	/* no-op's, complete with success */

This also needs a patch for sd.c to always use SYNCHRONIZE CACHE 16 for
ZBC drives.


-- 
Damien Le Moal
Western Digital Research