On May 09 2017 or thereabouts, Hans de Goede wrote: > Hi, > > On 09-05-17 09:12, Benjamin Tissoires wrote: > > Hi Hans, > > > > On May 07 2017 or thereabouts, Hans de Goede wrote: > > > ACPI devices which do not have a _PSC method are assumed to have been > > > put in D0 by the BIOS, but for touchscreens that is not always true, > > > so call acpi_device_fix_up_power to explicitly put devices without a > > > _PSC method into D0 state. > > > > > > This fixes the SIS0817 i2c-hid touchscreen on a Peaq C1010 2-in-1 > > > device failing to probe with a "hid_descr_cmd failed" error. > > > > > > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > > > --- > > > drivers/hid/i2c-hid/i2c-hid.c | 13 +++++++++++++ > > > 1 file changed, 13 insertions(+) > > > > > > diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c > > > index ea3c3546cef7..c716d9605940 100644 > > > --- a/drivers/hid/i2c-hid/i2c-hid.c > > > +++ b/drivers/hid/i2c-hid/i2c-hid.c > > > @@ -960,6 +960,15 @@ static int i2c_hid_acpi_pdata(struct i2c_client *client, > > > return 0; > > > } > > > +static void i2c_hid_acpi_fix_up_power(struct device *dev) > > > +{ > > > + acpi_handle handle = ACPI_HANDLE(dev); > > > + struct acpi_device *adev; > > > + > > > + if (handle && acpi_bus_get_device(handle, &adev) == 0) > > > + acpi_device_fix_up_power(adev); > > > > I am wondering if this is not something that should be handled by > > acpi-core or i2c-core. Looks like something pretty generic. > > The acpi-core deliberately does not do this, as unconditionally > doing this for all devices is known to break things on some > platforms, see: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7cd8407 > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b9e95fc65eded > > So calling this is something which needs to be done an a device-by-device > (usually actually on a driver-by-driver) basis. > > I don't expect this to cause any problems for i2c-hid devices > (as the above commits shown once it was done for all ACPI enumerated devices) > and it is necessary for some i2c-hid devices. > > > Also, isn't this also needed on resume (or reset_resume)? > > After a suspend the device is in D3, so we will always execute _PS0 > to put it back in D0. This is about devices without a _PSC method > (which allows querying the actual state) being in D3 on boot, rather > then the expected (and assumed) D0. Note that for devices with a _PSC > method calling acpi_device_fix_up_power() is a nop. > Thanks for the extensive explanations. Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Maybe we can add this to the commit message for future reference? Cheers, Benjamin > Regards, > > Hans > > > > +} > > > + > > > static const struct acpi_device_id i2c_hid_acpi_match[] = { > > > {"ACPI0C50", 0 }, > > > {"PNP0C50", 0 }, > > > @@ -972,6 +981,8 @@ static inline int i2c_hid_acpi_pdata(struct i2c_client *client, > > > { > > > return -ENODEV; > > > } > > > + > > > +static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {} > > > #endif > > > #ifdef CONFIG_OF > > > @@ -1070,6 +1081,8 @@ static int i2c_hid_probe(struct i2c_client *client, > > > if (ret < 0) > > > goto err; > > > + i2c_hid_acpi_fix_up_power(&client->dev); > > > + > > > pm_runtime_get_noresume(&client->dev); > > > pm_runtime_set_active(&client->dev); > > > pm_runtime_enable(&client->dev); > > > -- > > > 2.12.2 > > > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html