Re: [PATCH] scsi: ufs: Allow RTT negotiation

From: Bean Huo
Date: Thu May 02 2024 - 15:51:17 EST


Avri,

On 02.05.24 3:19 PM, Avri Altman wrote:
+ /* RTT override makes sense only for UFS-4.0 and above */
+ if (dev_info->wspecversion < 0x400)
+ return;
+
+ rtt = min_t(int, desc_buf[DEVICE_DESC_PARAM_RTT_CAP], hba->nortt);
+ /* rtt is 2 after manufacturing */
+ if (rtt < 3)
+ return;
+
+ if (ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+ QUERY_ATTR_IDN_MAX_NUM_OF_RTT, 0, 0, &rtt))
+ dev_err(hba->dev, "failed writing bMaxNumOfRTT\n");
+}

bMaxNumOfRTT is Persistent Property,  do we need to re-write every time power cycle?

Kind regards,

Bean