Re: [PATCH v3 1/1] platform/chrome: Poke kb_wake_angle attribute visibility when needed

From: Gwendal Grignou
Date: Wed Nov 16 2022 - 13:24:02 EST


[+chrome-platform@xxxxxxxxxxxxxxx]

On Mon, Nov 14, 2022 at 8:10 PM Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
>
> This patch is still needed to get the attribute to be present on most machines.
> Putting the attribute in the sensor hub device is more complicated, as
> that device is not as easily findable as `cros_ec`, present in
> `/sys/class`.
>
> Gwendal.
>
> On Wed, Aug 4, 2021 at 2:31 PM Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
> >
> > When the sensorhub detects 2 accelerometers, kb_wake_angle attribute
> > in the chromeos EC class device needs to be visible.
> > When detected, the sensorhub requests the class device to
> > revisit the visibility of the kb_wake_angle attribute.
> > Expose the attribute group to alter to close a potiential race between
> > cros-ec-sensorhub and cros-ec-sysfs (that creates the attribute group
> > on behalf of the class driver).
> >
> > Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> > ---
> > drivers/platform/chrome/cros_ec_sensorhub.c | 6 +++++-
> > drivers/platform/chrome/cros_ec_sysfs.c | 5 +++--
> > include/linux/platform_data/cros_ec_proto.h | 2 ++
> > 3 files changed, 10 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/platform/chrome/cros_ec_sensorhub.c b/drivers/platform/chrome/cros_ec_sensorhub.c
> > index 9c4af76a9956e..8f24ed90b229c 100644
> > --- a/drivers/platform/chrome/cros_ec_sensorhub.c
> > +++ b/drivers/platform/chrome/cros_ec_sensorhub.c
> > @@ -106,8 +106,12 @@ static int cros_ec_sensorhub_register(struct device *dev,
> > sensor_type[sensorhub->resp->info.type]++;
> > }
> >
> > - if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
> > + if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) {
> > ec->has_kb_wake_angle = true;
> > + if (ec->group && sysfs_update_group(&ec->class_dev.kobj,
> > + ec->group))
> > + dev_warn(dev, "Unable to update cros-ec-sysfs");
> > + }
> >
> > if (cros_ec_check_features(ec,
> > EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
> > diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c
> > index f07eabcf9494c..17fe657f3ffd5 100644
> > --- a/drivers/platform/chrome/cros_ec_sysfs.c
> > +++ b/drivers/platform/chrome/cros_ec_sysfs.c
> > @@ -341,7 +341,8 @@ static int cros_ec_sysfs_probe(struct platform_device *pd)
> > struct device *dev = &pd->dev;
> > int ret;
> >
> > - ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
> > + ec_dev->group = &cros_ec_attr_group;
> > + ret = sysfs_create_group(&ec_dev->class_dev.kobj, ec_dev->group);
> > if (ret < 0)
> > dev_err(dev, "failed to create attributes. err=%d\n", ret);
> >
> > @@ -352,7 +353,7 @@ static int cros_ec_sysfs_remove(struct platform_device *pd)
> > {
> > struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
> >
> > - sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
> > + sysfs_remove_group(&ec_dev->class_dev.kobj, ec_dev->group);
> >
> > return 0;
> > }
> > diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
> > index 02599687770c5..c6dca260bbd5d 100644
> > --- a/include/linux/platform_data/cros_ec_proto.h
> > +++ b/include/linux/platform_data/cros_ec_proto.h
> > @@ -191,6 +191,7 @@ struct cros_ec_platform {
> > /**
> > * struct cros_ec_dev - ChromeOS EC device entry point.
> > * @class_dev: Device structure used in sysfs.
> > + * @groups: sysfs attributes groups for this EC.
> > * @ec_dev: cros_ec_device structure to talk to the physical device.
> > * @dev: Pointer to the platform device.
> > * @debug_info: cros_ec_debugfs structure for debugging information.
> > @@ -200,6 +201,7 @@ struct cros_ec_platform {
> > */
> > struct cros_ec_dev {
> > struct device class_dev;
> > + const struct attribute_group *group;
> > struct cros_ec_device *ec_dev;
> > struct device *dev;
> > struct cros_ec_debugfs *debug_info;
> > --
> > 2.32.0.554.ge1b32706d8-goog
> >