scsi: ufs: fix multiple ufs spec violation

When a command to a W-LU is timed out via scsi, error handling
will treat it as any other LU and send commands such as
START_STOP with wrong format or task abort. Those commands are
illegal for W-LU according to the UFS spec.
To solve it, when an error is recognized those steps are skipped
and the last step, reset and restore process, is initiated.

Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 0b8c380392b9ffb57eccf0d2853dc460f54f64b0..a6a4a4302ca99efabf9ae886badff7a76843e2cb 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -218,6 +218,7 @@ static struct ufs_dev_fix ufs_fixups[] = {
 static void ufshcd_tmc_handler(struct ufs_hba *hba);
 static void ufshcd_async_scan(void *data, async_cookie_t cookie);
 static int ufshcd_reset_and_restore(struct ufs_hba *hba);
+static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd);
 static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
 static void ufshcd_hba_exit(struct ufs_hba *hba);
 static int ufshcd_probe_hba(struct ufs_hba *hba);
@@ -4730,6 +4731,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
        host = cmd->device->host;
        hba = shost_priv(host);
        tag = cmd->request->tag;
+       lrbp = &hba->lrb[tag];
        if (!ufshcd_valid_tag(hba, tag)) {
                dev_err(hba->dev,
                        "%s: invalid command tag %d: cmd=0x%p, cmd->request=0x%p",
@@ -4737,6 +4739,16 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
                BUG();
        }
 
+       /*
+        * Task abort to the device W-LUN is illegal. When this command
+        * will fail, due to spec violation, scsi err handling next step
+        * will be to send LU reset which, again, is a spec violation.
+        * To avoid these unnecessary/illegal step we skip to the last error
+        * handling stage: reset and restore.
+        */
+       if (lrbp->lun == UFS_UPIU_UFS_DEVICE_WLUN)
+               return ufshcd_eh_host_reset_handler(cmd);
+
        ufshcd_hold(hba, false);
        reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
        /* If command is already aborted/completed, return SUCCESS */
@@ -4760,7 +4772,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
        ufshcd_print_pwr_info(hba);
        ufshcd_print_trs(hba, 1 << tag, true);
 
-       lrbp = &hba->lrb[tag];
        for (poll_cnt = 100; poll_cnt; poll_cnt--) {
                err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
                                UFS_QUERY_TASK, &resp);