Re: [PATCH 5/6] scsi: ufs: ufs-sysfs: Expose UFS power info

[Can Guo]

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@xxxxxxxxxxx>
> > ---
> >   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.