From: Peter Wang <peter.wang@xxxxxxxxxxxx>
When a SCSI abort occurs, ufshcd_try_to_abort_task may trigger
the ISR, and the ISR may release the command and notify SCSI
via scsi_done. This patch prevents the ISR from notifying
SCSI to requeue, allowing SCSI to decide whether to requeue.
Below is ufshcd_abort legacy SDB flow:
ufshcd_abort()
ufshcd_try_to_abort_task() // will trigger ISR
get outstanding_lock
clear outstanding_reqs tag
ufshcd_release_scsi_cmd()
release outstanding_lock
ufshcd_intr()
ufshcd_sl_intr()
ufshcd_transfer_req_compl()
ufshcd_poll()
get outstanding_lock
clear outstanding_reqs tag
release outstanding_lock
__ufshcd_transfer_req_compl()
ufshcd_compl_one_cqe()
cmd->result = DID_REQUEUE
ufshcd_release_scsi_cmd()
scsi_done();
In most cases, ufshcd_intr will not reach scsi_done because the
outstanding_reqs tag is cleared by the original thread.
Therefore, whether there is an interrupt or not doesn't affect
the result because the ISR will do nothing in most cases.
In a very low chance, the ISR will reach scsi_done and notify
SCSI to requeue, and the original thread will not
call ufshcd_release_scsi_cmd. So should release because
outstanding_reqs is clear by ISR.
Below is ufshcd_abort MCQ flow:
ufshcd_abort()
ufshcd_mcq_abort()
ufshcd_try_to_abort_task() // will trigger ISR
ufshcd_release_scsi_cmd()
ufs_mtk_mcq_intr()
ufshcd_mcq_poll_cqe_lock()
ufshcd_mcq_process_cqe()
ufshcd_compl_one_cqe()
cmd->result = DID_ABORT
ufshcd_release_scsi_cmd() // will release twice
scsi_done()
In the case of MCQ ufshcd_abort, there is an issue where
ufshcd_release_scsi_cmd might be called twice. We could simply
skip the ISR release and scsi_done.
Signed-off-by: Peter Wang <peter.wang@xxxxxxxxxxxx>
---
drivers/ufs/core/ufs-mcq.c | 6 ++++++
drivers/ufs/core/ufshcd.c | 27 +++++++++++++++++++++++++++
include/ufs/ufshcd.h | 1 +
3 files changed, 34 insertions(+)
diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 3903947dbed1..73d7cf337e2f 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -699,6 +699,12 @@ int ufshcd_mcq_abort(struct scsi_cmnd *cmd)
return FAILED;
}
+ /*
+ * In MCQ mode, set this variable so that the ISR posted by
+ * the host controller can be skipped.
+ */
+ lrbp->abort_initiated_by = UFS_SCSI_ABORT;
+
/*
* The command is not in the submission queue, and it is not
* in the completion queue either. Query the device to see if
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index b34125238a70..21091b11b4ba 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5537,6 +5537,27 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
ufshcd_update_monitor(hba, lrbp);
ufshcd_add_command_trace(hba, task_tag, UFS_CMD_COMP);
cmd->result = ufshcd_transfer_rsp_status(hba, lrbp, cqe);
+
+ /*
+ * Let the SCSI layer decide how to handle the ufshcd_abort
+ * situation, neither releasing nor notifying scsi_done in MCQ
+ * mode. SDB mode should release because outstanding_reqs is
+ * clear by ISR.
+ */
+ if (lrbp->abort_initiated_by == UFS_SCSI_ABORT) {
+ ocs = ufshcd_get_tr_ocs(lrbp, cqe);
+ if ((hba->mcq_enabled) && (ocs == OCS_ABORTED))
+ return;
+
+ if ((!hba->mcq_enabled) &&
+ ((ocs == OCS_INVALID_COMMAND_STATUS) ||
+ ((hba->quirks & UFSHCD_QUIRK_OCS_ABORTED) &&
+ (ocs == OCS_ABORTED)))) {
+ ufshcd_release_scsi_cmd(hba, lrbp);
+ return;
+ }
+ }
+
ufshcd_release_scsi_cmd(hba, lrbp);
/* Do not touch lrbp after scsi done */
scsi_done(cmd);
@@ -7673,6 +7694,12 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
goto release;
}
+ /*
+ * In SDB mode, set this variable so that the ISR posted by
+ * the host controller clear UTRLCLR can be skipped.
+ */
+ lrbp->abort_initiated_by = UFS_SCSI_ABORT;
+
err = ufshcd_try_to_abort_task(hba, tag);
if (err) {
dev_err(hba->dev, "%s: failed with err %d\n", __func__, err);
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 4d17a13ac558..4785a45040eb 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -148,6 +148,7 @@ enum ufs_pm_level {
enum ufs_abort_by {
UFS_NO_ABORT,
UFS_ERR_HANDLER,
+ UFS_SCSI_ABORT
};
struct ufs_pm_lvl_states {
--
2.45.2
