On Wed, Mar 23, 2016 at 03:58:31PM -0700, Dmitry Torokhov wrote: > From: Dmitry Torokhov <[email protected]> > > When firmware does not use _DSD properties that allow properly name GPIO > resources, the kernel falls back on parsing _CRS resources, and will > return entries described as GpioInt() as general purpose GPIOs even > though they are meant to be used simply as interrupt sources for the > device: > > Device (ETSA) > { > Name (_HID, "ELAN0001") > ... > > Method(_CRS, 0x0, NotSerialized) > { > Name(BUF0,ResourceTemplate () > { > I2CSerialBus( > 0x10, /* SlaveAddress */ > ControllerInitiated, /* SlaveMode */ > 400000, /* ConnectionSpeed */ > AddressingMode7Bit, /* AddressingMode */ > "\\_SB.I2C1", /* ResourceSource */ > ) > GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone,, > "\\_SB.GPSW") { BOARD_TOUCH_GPIO_INDEX } > } ) > Return (BUF0) > } > ... > } > > This gives troubles with drivers such as Elan Touchscreen driver > (elants_i2c) that uses devm_gpio_get to look up "reset" GPIO line and > decide whether the driver is responsible for powering up and resetting > the device or firmware is. In the above case the lookup succeeds, we map > GPIO as output and later fail to request client->irq interrupt that is > mapped to the same GPIO. > > Let's ignore resources described as GpioInt() when requesting output > GPIO (but allow them when requesting GPIOD_ASIS or GPIOD_IN as some > drivers - i2c-hid - do request GPIO as input and then map it to > interrupt with gpiod_to_irq).
You could mention here that we only ignore GpioInt() resources in fallback case. > BUG=chrome-os-partner:51154 > TEST=Boot Cyan, verify touchscreen work > > Change-Id: Id20c730b937dce8a4135d2b64c8d798372d20e82 This is not needed for mainline patches :) > Signed-off-by: Dmitry Torokhov <[email protected]> Acked-by: Mika Westerberg <[email protected]>
