Re: [PATCH v1 1/1] scsi: ufs: core: add device level exception support

["Bao D. Nguyen" <quic_nguyenb@quicinc.com>]

On 3/13/2025 10:28 AM, Manivannan Sadhasivam wrote:
>> +
>> +What:		/sys/bus/platform/drivers/ufshcd/*/device_lvl_exception
>> +What:		/sys/bus/platform/devices/*.ufs/device_lvl_exception
>> +Date:		March 2025
>> +Contact:	Bao D. Nguyen <quic_nguyenb@quicinc.com>
>> +Description:
>> +		The device_lvl_exception is a counter indicating the number
>> +		of times the device level exceptions have occurred since the
>> +		last time this variable is reset. Read the device_lvl_exception_id
>> +		sysfs node to know more information about the exception.
>> +		The file is read only.
> 
> No. This attribute is RW and the write of 0 will reset the counter. Please
> change it here and also in commit message.
> 
> Also document the spec version requirement for these attributes.
> 
Thank you Mani. I will make corrections.

>> +
>> +What:		/sys/bus/platform/drivers/ufshcd/*/device_lvl_exception_id
>> +What:		/sys/bus/platform/devices/*.ufs/device_lvl_exception_id
>> +Date:		March 2025
>> +Contact:	Bao D. Nguyen <quic_nguyenb@quicinc.com>
>> +Description:
>> +		Reading the device_lvl_exception_id returns the device JEDEC
>> +		standard's qDeviceLevelExceptionID attribute. The definition of the
>> +		qDeviceLevelExceptionID is the ufs device vendor specific design.
>> +		Refer to the device manufacturer datasheet for more information
>> +		on the meaning of the qDeviceLevelExceptionID attribute value.
>> +		The file is read only.
>> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
>> index 90b5ab6..0248288a 100644
>> --- a/drivers/ufs/core/ufs-sysfs.c
>> +++ b/drivers/ufs/core/ufs-sysfs.c
>> @@ -466,6 +466,56 @@ static ssize_t critical_health_show(struct device *dev,
>>   	return sysfs_emit(buf, "%d\n", hba->critical_health_count);
>>   }
>>   
> 
> [...]
> 
>> +int ufshcd_read_device_lvl_exception_id(struct ufs_hba *hba, u64 *exception_id)
>> +{
>> +	struct utp_upiu_query_response_v4_0 *upiu_resp;
>> +	struct ufs_query_req *request = NULL;
>> +	struct ufs_query_res *response = NULL;
>> +	int err;
>> +
>> +	if (hba->dev_info.wspecversion < 0x410)
>> +		return -EOPNOTSUPP;
>> +
>> +	ufshcd_hold(hba);
>> +	mutex_lock(&hba->dev_cmd.lock);
>> +
>> +	ufshcd_init_query(hba, &request, &response,
>> +			  UPIU_QUERY_OPCODE_READ_ATTR,
>> +			  QUERY_ATTR_IDN_DEV_LVL_EXCEPTION_ID, 0, 0);
>> +
>> +	request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
>> +
>> +	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
>> +
>> +	if (err) {
>> +		dev_err(hba->dev, "%s: failed to read device level exception %d\n",
>> +			__func__, err);
>> +		goto out;
>> +	}
>> +
>> +	upiu_resp = (struct utp_upiu_query_response_v4_0 *)response;
>> +	*exception_id = get_unaligned_be64(&upiu_resp->value);
>> +
>> +out:
>> +	mutex_unlock(&hba->dev_cmd.lock);
>> +	ufshcd_release(hba);
>> +
>> +	return err;
>> +}
>> +EXPORT_SYMBOL_GPL(ufshcd_read_device_lvl_exception_id);
> 
> There is no need to export this function.
>
I will make the correction.

> - Mani
>