Hi,
On 10-02-17 12:52, 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.
But unfortunately it causes regressions for drivers which actually use
gpiod_get_by_index, e.g. drivers/extcon/extcon-intel-int3496.c, which
does:
data->gpio_usb_id = devm_gpiod_get_index(dev, "id",
INT3496_GPIO_USB_ID,
GPIOD_IN);
Where GPIOD_IN is 0, (it also gets gpios for index 1 and 2), I guess
this driver can be fixed by replacing "id" with NULL, but the name
gets used in things like /sys/kernel/debug/gpio and is actually
useful there, so it looks like that patch from Andy needs some
work so as to not see getting by index as an undesirable fallback
while the driver is actually doing a request gpio by index.
Regards,
Hans
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