On Thu, Mar 24, 2016 at 7:01 AM, Mika Westerberg <[email protected]> wrote: > 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.
I thought I did that (in the first paragraph). Let me try to reword better and resend. > >> BUG=chrome-os-partner:51154 >> TEST=Boot Cyan, verify touchscreen work >> >> Change-Id: Id20c730b937dce8a4135d2b64c8d798372d20e82 > > This is not needed for mainline patches :) Ugh, sorry, I forgot to cut this stuff out... > >> Signed-off-by: Dmitry Torokhov <[email protected]> > > Acked-by: Mika Westerberg <[email protected]> Thanks. -- Dmitry
