From: Luo Jiaxing <luojiaxing@huawei.com> mainline inclusion from mainline-v5.9-rc5 commit 53de092f47ff40e8d4d78d590d95819d391bf2e0 category: bugfix bugzilla: NA CVE: NA -------------------------------- It was discovered that sdparm will fail when attempting to disable write cache on a SATA disk connected via libsas. In the ATA command set the write cache state is controlled through the SET FEATURES operation. This is roughly corresponds to MODE SELECT in SCSI and the latter command is what is used in the SCSI-ATA translation layer. A subtle difference is that a MODE SELECT carries data whereas SET FEATURES is defined as a non-data command in ATA. Set the DMA data direction to DMA_NONE if the requested ATA command is identified as non-data. [mkp: commit desc] Fixes: fa1c1e8f1ece ("[SCSI] Add SATA support to libsas") Link: https://lore.kernel.org/r/1598426666-54544-1-git-send-email-luojiaxing@huawe... Reviewed-by: John Garry <john.garry@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/scsi/libsas/sas_ata.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c index 67bf9eafe6d9..74f87da00720 100644 --- a/drivers/scsi/libsas/sas_ata.c +++ b/drivers/scsi/libsas/sas_ata.c @@ -223,7 +223,10 @@ static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc) task->num_scatter = si; } - task->data_dir = qc->dma_dir; + if (qc->tf.protocol == ATA_PROT_NODATA) + task->data_dir = DMA_NONE; + else + task->data_dir = qc->dma_dir; task->scatter = qc->sg; task->ata_task.retry_count = 1; task->task_state_flags = SAS_TASK_STATE_PENDING; -- 2.25.1