Message ID | 20170523170327.18055-5-andriy.shevchenko@linux.intel.com |
---|---|
State | New |
Headers | show |
On Tue, May 23, 2017 at 7:03 PM, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > 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> Patch applied. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 28f35a9de86b..0392d8ed332f 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -1129,45 +1129,11 @@ int acpi_gpio_count(struct device *dev, const char *con_id) return count ? count : -ENOENT; } -struct acpi_crs_lookup { - struct list_head node; - struct acpi_device *adev; - const char *con_id; -}; - -static DEFINE_MUTEX(acpi_crs_lookup_lock); -static LIST_HEAD(acpi_crs_lookup_list); - bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id) { - struct acpi_crs_lookup *l, *lookup = NULL; - /* Never allow fallback if the device has properties */ if (adev->data.properties || adev->driver_gpios) return false; - mutex_lock(&acpi_crs_lookup_lock); - - list_for_each_entry(l, &acpi_crs_lookup_list, node) { - if (l->adev == adev) { - lookup = l; - break; - } - } - - if (!lookup) { - lookup = kmalloc(sizeof(*lookup), GFP_KERNEL); - if (lookup) { - lookup->adev = adev; - lookup->con_id = kstrdup(con_id, GFP_KERNEL); - list_add_tail(&lookup->node, &acpi_crs_lookup_list); - } - } - - mutex_unlock(&acpi_crs_lookup_lock); - - return lookup && - ((!lookup->con_id && !con_id) || - (lookup->con_id && con_id && - strcmp(lookup->con_id, con_id) == 0)); + return con_id == NULL; }