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Message-ID: <d38e6329-a44d-73af-6675-13395c4c5200@quicinc.com>
Date:   Fri, 15 Sep 2023 09:59:29 +0800
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Subject: Re: [PATCH 5/6] scsi: ufs: ufs-sysfs: Expose UFS power info
Content-Language: en-US
To:     Nitin Rawat <quic_nitirawa@quicinc.com>, <mani@kernel.org>,
        <quic_nguyenb@quicinc.com>, <martin.petersen@oracle.com>
CC:     <linux-scsi@vger.kernel.org>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        "Avri Altman" <avri.altman@wdc.com>,
        Bart Van Assche <bvanassche@acm.org>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        Bean Huo <beanhuo@micron.com>,
        "Arthur Simchaev" <arthur.simchaev@wdc.com>,
        Lu Hongfei <luhongfei@vivo.com>,
        "open list" <linux-kernel@vger.kernel.org>
References: <1694411968-14413-1-git-send-email-quic_cang@quicinc.com>
 <1694411968-14413-6-git-send-email-quic_cang@quicinc.com>
 <8a9cc52c-9c7d-1f8f-8a98-1a816f59aa79@quicinc.com>
From:   Can Guo <quic_cang@quicinc.com>
In-Reply-To: <8a9cc52c-9c7d-1f8f-8a98-1a816f59aa79@quicinc.com>
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Precedence: bulk

Hi Nitin,

On 9/14/2023 7:33 PM, Nitin Rawat wrote:
>
>
> On 9/11/2023 11:29 AM, Can Guo wrote:
>> Having UFS power info available in sysfs makes it easier to tell the 
>> state
>> of the link during runtime considering we have a bounch of power saving
>> features and various combinations for backward compatiblity.
>
> Please fix spelling mistake - *bounch -> bunch
done
>
>
>>
>> Signed-off-by: Can Guo <quic_cang@quicinc.com>
>> ---
>>   drivers/ufs/core/ufs-sysfs.c | 71 
>> ++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 71 insertions(+)
>>
>> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
>> index c959064..53af490 100644
>> --- a/drivers/ufs/core/ufs-sysfs.c
>> +++ b/drivers/ufs/core/ufs-sysfs.c
>> @@ -628,6 +628,76 @@ static const struct attribute_group 
>> ufs_sysfs_monitor_group = {
>>       .attrs = ufs_sysfs_monitor_attrs,
>>   };
>>   +static ssize_t gear_show(struct device *dev, struct 
>> device_attribute *attr,
>> +             char *buf)
>> +{
>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +    return sysfs_emit(buf, "%u\n", hba->pwr_info.gear_rx);
>> +}
>> +
>> +static ssize_t lane_show(struct device *dev, struct device_attribute 
>> *attr,
>> +             char *buf)
>> +{
>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +    return sysfs_emit(buf, "%u\n", hba->pwr_info.lane_rx);
>> +}
>> +
>> +static ssize_t mode_show(struct device *dev, struct device_attribute 
>> *attr,
>> +             char *buf)
>> +{
>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +    return sysfs_emit(buf, "%u\n", hba->pwr_info.pwr_rx);
>> +}
>> +
>> +static ssize_t rate_show(struct device *dev, struct device_attribute 
>> *attr,
>> +             char *buf)
>> +{
>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +    return sysfs_emit(buf, "%u\n", hba->pwr_info.hs_rate);
>> +}
>> +
>> +static ssize_t dev_pm_show(struct device *dev, struct 
>> device_attribute *attr,
>> +               char *buf)
>> +{
>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +    return sysfs_emit(buf, "%d\n", hba->curr_dev_pwr_mode);
>> +}
>> +
>> +static ssize_t link_state_show(struct device *dev,
>> +                   struct device_attribute *attr, char *buf)
>> +{
>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +    return sysfs_emit(buf, "%d\n", hba->uic_link_state);
>> +}
>> +
>> +static DEVICE_ATTR_RO(gear);
>> +static DEVICE_ATTR_RO(lane);
>> +static DEVICE_ATTR_RO(mode);
>> +static DEVICE_ATTR_RO(rate);
>> +static DEVICE_ATTR_RO(dev_pm);
>> +static DEVICE_ATTR_RO(link_state);
>> +
>> +static struct attribute *ufs_power_info_attrs[] = {
>> +    &dev_attr_gear.attr,
>> +    &dev_attr_lane.attr,
>> +    &dev_attr_mode.attr,
>> +    &dev_attr_rate.attr,
>> +    &dev_attr_dev_pm.attr,
>> +    &dev_attr_link_state.attr,
>> +    NULL
>> +};
>> +
>> +static const struct attribute_group ufs_sysfs_power_info_group = {
>> +    .name = "power_info",
>> +    .attrs = ufs_power_info_attrs,
>> +};
>> +
>>   static ssize_t ufs_sysfs_read_desc_param(struct ufs_hba *hba,
>>                     enum desc_idn desc_id,
>>                     u8 desc_index,
>> @@ -1233,6 +1303,7 @@ static const struct attribute_group 
>> *ufs_sysfs_groups[] = {
>>       &ufs_sysfs_default_group,
>>       &ufs_sysfs_capabilities_group,
>>       &ufs_sysfs_monitor_group,
>> +    &ufs_sysfs_power_info_group,
>>       &ufs_sysfs_device_descriptor_group,
>>       &ufs_sysfs_interconnect_descriptor_group,
>>       &ufs_sysfs_geometry_descriptor_group,
>
>
> How about having one power mode attribute displaying all useful info 
> (lane, gear, mode, rate).

sysfs entry is meant for printing a single value instead of a line of 
strings.

>
> Regards,
> Nitin Rawat


Thanks,

Can Guo.