scsi: ufs: Fix ufshcd_request_sense_async() for Samsung KLUFG8RHDA-B2D1

Samsung KLUFG8RHDA-B2D1 does not clear the unit attention condition if the
length is zero. So go back to requesting all the sense data, as it was
before patch "scsi: ufs: Request sense data asynchronously". That is
simpler than creating and maintaining a quirk for affected devices.

Link: https://lore.kernel.org/r/20210824114150.2105-1-adrian.hunter@intel.com
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
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 a3b4198..3841ab4 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7937,7 +7937,8 @@ out:
 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);
+               pr_err("%s: REQUEST SENSE failed (%d)\n", __func__, error);
+       kfree(rq->end_io_data);
        blk_put_request(rq);
 }
 
@@ -7945,16 +7946,30 @@ static int
 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.
+        * Some UFS devices clear unit attention condition only if the sense
+        * size used (UFS_SENSE_SIZE in this case) is non-zero.
         */
-       static const u8 cmd[6] = {REQUEST_SENSE, 0, 0, 0, 0, 0};
+       static const u8 cmd[6] = {REQUEST_SENSE, 0, 0, 0, UFS_SENSE_SIZE, 0};
        struct scsi_request *rq;
        struct request *req;
+       char *buffer;
+       int ret;
 
-       req = blk_get_request(sdev->request_queue, REQ_OP_DRV_IN, /*flags=*/0);
-       if (IS_ERR(req))
-               return PTR_ERR(req);
+       buffer = kzalloc(UFS_SENSE_SIZE, GFP_KERNEL);
+       if (!buffer)
+               return -ENOMEM;
+
+       req = blk_get_request(sdev->request_queue, REQ_OP_DRV_IN,
+                             /*flags=*/BLK_MQ_REQ_PM);
+       if (IS_ERR(req)) {
+               ret = PTR_ERR(req);
+               goto out_free;
+       }
+
+       ret = blk_rq_map_kern(sdev->request_queue, req,
+                             buffer, UFS_SENSE_SIZE, GFP_NOIO);
+       if (ret)
+               goto out_put;
 
        rq = scsi_req(req);
        rq->cmd_len = ARRAY_SIZE(cmd);
@@ -7962,10 +7977,17 @@ ufshcd_request_sense_async(struct ufs_hba *hba, struct scsi_device *sdev)
        rq->retries = 3;
        req->timeout = 1 * HZ;
        req->rq_flags |= RQF_PM | RQF_QUIET;
+       req->end_io_data = buffer;
 
        blk_execute_rq_nowait(/*bd_disk=*/NULL, req, /*at_head=*/true,
                              ufshcd_request_sense_done);
        return 0;
+
+out_put:
+       blk_put_request(req);
+out_free:
+       kfree(buffer);
+       return ret;
 }
 
 static int ufshcd_clear_ua_wlun(struct ufs_hba *hba, u8 wlun)