On Fri, Feb 10, 2017 at 12:52:41PM +0100, Hans de Goede wrote:
> Hi,
>
> On 02-02-17 14:12, Mika Westerberg wrote:
> > On Thu, Feb 02, 2017 at 01:50:58PM +0100, Hans de Goede wrote:
> > > Hi,
> > >
> > > On 02-02-17 13:32, Mika Westerberg wrote:
> > > > On Thu, Feb 02, 2017 at 02:10:18PM +0200, Mika Westerberg wrote:
> > > > > I do not have a copy of the patch in this thread but sounds like
> > > > > something that might work.
> > > >
> > > > Actually, I seem have a copy of that patch.
> > > >
> > > > So you are saying that the device has a power GPIO in ACPI _CRS but it
> > > > should not be used for some reason?
> > >
> > > Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Setti
> > > {
> > > Name (WBUF, ResourceTemplate ()
> > > {
> > > I2cSerialBusV2 (0x0040, ControllerInitiated, 0x00061A80,
> > > AddressingMode7Bit, "\\_SB.PCI0.I2C6",
> > > 0x00, ResourceConsumer, , Exclusive,
> > > )
> > > GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestri
> > > "\\_SB.GPO1", 0x00, ResourceConsumer, ,
> > > )
> > > { // Pin list
> > > 0x0019
> > > }
> > > GpioInt (Edge, ActiveHigh, Shared, PullDefault, 0x0000,
> > > "\\_SB.GPO1", 0x00, ResourceConsumer, ,
> > > )
> > > { // Pin list
> > > 0x0013
> > > }
> > > })
> > > Return (WBUF) /* \_SB_.PCI0.I2C6.TCS4._CRS.WBUF */
> > > }
> > >
> > > The setting of the special bit in the gpio control register leads to
> > > drivers/pinctrl/intel/pinctrl-cherryview.c chv_gpio_request_enable()
> > > returning -EBUSY, which in return makes gpiod_get_optional
> > > return -EBUSY for this pin, rather then NULL (as we would like).
> >
> > Actually what is wrong here is that your gpiod_get(dev, "power") falls
> > back to use plain indexes and returns the first GPIO even though it
> > should not as the driver specifically requests GPIO with name "power"
> > and there is no _DSD.
> >
> > Andy (Cc'd) has a patch that tries to make the fallback mechanism more
> > stricter which should in theory fix the problem as well. The patch
> > series is here:
> >
> > https://bitbucket.org/andy-shev/linux/commits/338c0226b631b8b497d143070a301d8b8883c349?at=master
>
> Ok, that patches fixes the issues I was seeing with the silead driver
> on my cube iwork8 air cherrytrail tablet.
OK, good to hear. I suppose Andy can start cleaning up that branch and
send them for review then ;-)
> As discussed we might need some extra handling to fallback to actually
> get a gpio by index on some tablets which don't control the gpio from
> ACPI AML code, but lets cross that bridge when we get there.
Agreed.
--
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
