@@ -7820,8 +7820,39 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
return ret;
}
+static void ufshcd_request_sense_done(struct request *rq, blk_status_t error)
+{
+ if (error != BLK_STS_OK)
+ pr_err("%s: REQUEST SENSE failed (%d)", __func__, error);
+ blk_put_request(rq);
+}
+
static int
-ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device *sdp);
+ufshcd_request_sense_async(struct ufs_hba *hba, struct scsi_device *sdev)
+{
+ /*
+ * From SPC-6: the REQUEST SENSE command with any allocation length
+ * clears the sense data.
+ */
+ static const u8 cmd[6] = {REQUEST_SENSE, 0, 0, 0, 0, 0};
+ struct scsi_request *rq;
+ struct request *req;
+
+ req = blk_get_request(sdev->request_queue, REQ_OP_DRV_IN, /*flags=*/0);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ rq = scsi_req(req);
+ rq->cmd_len = ARRAY_SIZE(cmd);
+ memcpy(rq->cmd, cmd, rq->cmd_len);
+ rq->retries = 3;
+ req->timeout = 1 * HZ;
+ req->rq_flags |= RQF_PM | RQF_QUIET;
+
+ blk_execute_rq_nowait(/*bd_disk=*/NULL, req, /*at_head=*/true,
+ ufshcd_request_sense_done);
+ return 0;
+}
static int ufshcd_clear_ua_wlun(struct ufs_hba *hba, u8 wlun)
{
@@ -7849,7 +7880,7 @@ static int ufshcd_clear_ua_wlun(struct ufs_hba *hba, u8 wlun)
if (ret)
goto out_err;
- ret = ufshcd_send_request_sense(hba, sdp);
+ ret = ufshcd_request_sense_async(hba, sdp);
scsi_device_put(sdp);
out_err:
if (ret)
@@ -8444,35 +8475,6 @@ static void ufshcd_hba_exit(struct ufs_hba *hba)
}
}
-static int
-ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device *sdp)
-{
- unsigned char cmd[6] = {REQUEST_SENSE,
- 0,
- 0,
- 0,
- UFS_SENSE_SIZE,
- 0};
- char *buffer;
- int ret;
-
- buffer = kzalloc(UFS_SENSE_SIZE, GFP_KERNEL);
- if (!buffer) {
- ret = -ENOMEM;
- goto out;
- }
-
- ret = scsi_execute(sdp, cmd, DMA_FROM_DEVICE, buffer,
- UFS_SENSE_SIZE, NULL, NULL,
- msecs_to_jiffies(1000), 3, 0, RQF_PM, NULL);
- if (ret)
- pr_err("%s: failed with err %d\n", __func__, ret);
-
- kfree(buffer);
-out:
- return ret;
-}
-
/**
* ufshcd_set_dev_pwr_mode - sends START STOP UNIT command to set device
* power mode
Clearing a unit attention synchronously from inside the UFS error handler may trigger the following deadlock: - ufshcd_err_handler() calls ufshcd_err_handling_unprepare() and the latter function calls ufshcd_clear_ua_wluns(). - ufshcd_clear_ua_wluns() submits a REQUEST SENSE command and that command activates the SCSI error handler. - The SCSI error handler calls ufshcd_host_reset_and_restore(). - ufshcd_host_reset_and_restore() executes the following code: ufshcd_schedule_eh_work(hba); flush_work(&hba->eh_work); This sequence results in a deadlock (circular wait). Fix this by requesting sense data asynchronously. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Stanley Chu <stanley.chu@mediatek.com> Cc: Can Guo <cang@codeaurora.org> Cc: Asutosh Das <asutoshd@codeaurora.org> Cc: Avri Altman <avri.altman@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/ufs/ufshcd.c | 64 ++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 31 deletions(-)