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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2017-05-23 19:03:19 +0200
committerLinus Walleij <linus.walleij@linaro.org>2017-05-29 11:17:51 +0200
commitf10e4bf6632b5be11cea875b66ba959833a69258 (patch)
tree9dc8243e13ba4264bb2d255acd82c480cdc16546 /drivers/gpio/gpio-dwapb.c
parentgpio: acpi: Do sanity check for GpioInt in acpi_find_gpio() (diff)
downloadlinux-f10e4bf6632b5be11cea875b66ba959833a69258.tar.xz
linux-f10e4bf6632b5be11cea875b66ba959833a69258.zip
gpio: acpi: Even more tighten up ACPI GPIO lookups
The commit 10cf4899f8af ("gpiolib: tighten up ACPI legacy gpio lookups") prevents to getting same resource twice if the driver asks twice using different connection ID. But the whole idea of fallback might bring some problems. Imagine the case when we have two versions of BIOS/hardware where in one _DSD is introduced along with GPIO resources, but the other one uses just plain GPIO resource for another purpose Case 1: Device (DEVX) { ... Name (_CRS, ResourceTemplate () { GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly, "\\_SB.GPO0", 0, ResourceConsumer) {15} }) Name (_DSD, Package () { ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), Package () { Package () {"some-gpios", Package() {^DEVX, 0, 0, 0 }}, } }) } Case 2: Device (DEVX) { ... Name (_CRS, ResourceTemplate () { GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly, "\\_SB.GPO0", 0, ResourceConsumer) {27} }) } To prevent the possible misconfiguration tighten up even more GPIO ACPI lookups for case without connection ID provided. In the past the issue had been triggered by "use mctrl_gpio helpers" series [1,2]. [1] commit 4ef03d328769 ("tty/serial/8250: use mctrl_gpio helpers") [2] https://patchwork.kernel.org/patch/9283745/ Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Bastien Nocera <hadess@hadess.net> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-dwapb.c')
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