From: Tom Yan <tom.ty89@xxxxxxxxx> Example: [root@localhost ~]# sg_opcodes /dev/sdb > /dev/null Report supported operation codes: Illegal request, invalid opcode [root@localhost ~]# sg_vpd -p bl /dev/sdb | grep 'write same' Maximum write same length: 0x0 blocks [root@localhost ~]# cat /sys/block/sdb/queue/write_same_max_bytes 33553920 Signed-off-by: Tom Yan <tom.ty89@xxxxxxxxx> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index d749da7..1179ec1 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -807,6 +807,8 @@ static void sd_config_write_same(struct scsi_disk *sdkp) if (sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS) sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)SD_MAX_WS16_BLOCKS); + else if (sdkp->max_ws_blocks == 0 && sdkp->device->no_report_opcodes) + sdkp->device->no_write_same = 1; else if (sdkp->ws16 || sdkp->ws10 || sdkp->device->no_report_opcodes) sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)SD_MAX_WS10_BLOCKS); -- 2.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html