Re: [PATCH v2] iio: cros_ec: Use default frequencies when EC returns invalid information

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 30 Jun 2020 17:50:24 +0200
Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:

> Hi Gwendal,
> 
> On 30/6/20 17:37, Gwendal Grignou wrote:
> > Minimal and maximal frequencies supported by a sensor is queried.
> > On some older machines, these frequencies are not returned properly and
> > the EC returns 0 instead.
> > When returned maximal frequency is 0, ignore the information and use
> > default frequencies instead.
> > 
> > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>  
> 
> Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Fix or tidy up? I.e. does this want to go into stable?

Thanks,

Jonathan

> 
> > ---
> > Changes since v1:
> > - improve visibility by using new 100 character line length limit.
> > 
> >  .../cros_ec_sensors/cros_ec_sensors_core.c       | 16 +++++++++++-----
> >  1 file changed, 11 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > index 36e3f20891f05..b30fd6b56773f 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > @@ -289,7 +289,7 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> >  	struct cros_ec_sensorhub *sensor_hub = dev_get_drvdata(dev->parent);
> >  	struct cros_ec_dev *ec = sensor_hub->ec;
> >  	struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
> > -	u32 ver_mask;
> > +	u32 ver_mask, temp;
> >  	int frequencies[ARRAY_SIZE(state->frequencies) / 2] = { 0 };
> >  	int ret, i;
> >  
> > @@ -345,10 +345,16 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> >  						 &frequencies[2],
> >  						 &state->fifo_max_event_count);
> >  		} else {
> > -			frequencies[1] = state->resp->info_3.min_frequency;
> > -			frequencies[2] = state->resp->info_3.max_frequency;
> > -			state->fifo_max_event_count =
> > -			    state->resp->info_3.fifo_max_event_count;
> > +			if (state->resp->info_3.max_frequency == 0) {
> > +				get_default_min_max_freq(state->resp->info.type,
> > +							 &frequencies[1],
> > +							 &frequencies[2],
> > +							 &temp);
> > +			} else {
> > +				frequencies[1] = state->resp->info_3.min_frequency;
> > +				frequencies[2] = state->resp->info_3.max_frequency;
> > +			}
> > +			state->fifo_max_event_count = state->resp->info_3.fifo_max_event_count;
> >  		}
> >  		for (i = 0; i < ARRAY_SIZE(frequencies); i++) {
> >  			state->frequencies[2 * i] = frequencies[i] / 1000;
> >