scsi: ufs: core: Improve ufshcd_mcq_sq_cleanup()

From the UFSHCI specification: "CleanUp Command Return Code (RTC): host
controller sets this return code to provide more details of the cleanup
process. It is valid only when CUS is 1." Hence, do not read RTC if the
CUS bitfield is zero.

Cc: Bao D. Nguyen <[e-mail]>
Fixes: 8d7290348992 ("scsi: ufs: mcq: Add supporting functions for MCQ abort")
Signed-off-by: Bart Van Assche <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/ufs/core/ufs-mcq.c

···
 	/* SQRTCy.ICU = 1 */
 	writel(SQ_ICU, opr_sqd_base + REG_SQRTC);
 
-	/* Poll SQRTSy.CUS = 1. Return result from SQRTSy.RTC */
+	/* Wait until SQRTSy.CUS = 1. Report SQRTSy.RTC. */
 	reg = opr_sqd_base + REG_SQRTS;
 	err = read_poll_timeout(readl, val, val & SQ_CUS, 20,
 				MCQ_POLL_US, false, reg);
 	if (err)
-		dev_err(hba->dev, "%s: failed. hwq=%d, tag=%d err=%ld\n",
-			__func__, id, task_tag,
-			FIELD_GET(SQ_ICU_ERR_CODE_MASK, readl(reg)));
+		dev_err(hba->dev, "%s: failed. hwq=%d, tag=%d err=%d\n",
+			__func__, id, task_tag, err);
+	else
+		dev_info(hba->dev,
+			 "%s, hwq %d: cleanup return code (RTC) %ld\n",
+			 __func__, id,
+			 FIELD_GET(SQ_ICU_ERR_CODE_MASK, readl(reg)));
 
 	if (ufshcd_mcq_sq_start(hba, hwq))
 		err = -ETIMEDOUT;