Commit 46c42d84 authored by Brian Norris's avatar Brian Norris Committed by Greg Kroah-Hartman

driver core: platform: return -ENXIO for missing GpioInt

Commit daaef255 ("driver: platform: Support parsing GpioInt 0 in
platform_get_irq()") broke the Embedded Controller driver on most LPC
Chromebooks (i.e., most x86 Chromebooks), because cros_ec_lpc expects
platform_get_irq() to return -ENXIO for non-existent IRQs.
Unfortunately, acpi_dev_gpio_irq_get() doesn't follow this convention
and returns -ENOENT instead. So we get this error from cros_ec_lpc:

   couldn't retrieve IRQ number (-2)

I see a variety of drivers that treat -ENXIO specially, so rather than
fix all of them, let's fix up the API to restore its previous behavior.

I reported this on v2 of this patch:

https://lore.kernel.org/lkml/20190220180538.GA42642@google.com/

but apparently the patch had already been merged before v3 got sent out:

https://lore.kernel.org/lkml/20190221193429.161300-1-egranata@chromium.org/

and the result is that the bug landed and remains unfixed.

I differ from the v3 patch by:
 * allowing for ret==0, even though acpi_dev_gpio_irq_get() specifically
   documents (and enforces) that 0 is not a valid return value (noted on
   the v3 review)
 * adding a small comment
Reported-by: default avatarBrian Norris <briannorris@chromium.org>
Reported-by: default avatarSalvatore Bellizzi <salvatore.bellizzi@linux.seppia.net>
Cc: Enrico Granata <egranata@chromium.org>
Cc: <stable@vger.kernel.org>
Fixes: daaef255 ("driver: platform: Support parsing GpioInt 0 in platform_get_irq()")
Signed-off-by: default avatarBrian Norris <briannorris@chromium.org>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarEnrico Granata <egranata@google.com>
Link: https://lore.kernel.org/r/20190729204954.25510-1-briannorris@chromium.orgSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5f9e832c
...@@ -157,8 +157,13 @@ int platform_get_irq(struct platform_device *dev, unsigned int num) ...@@ -157,8 +157,13 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
* the device will only expose one IRQ, and this fallback * the device will only expose one IRQ, and this fallback
* allows a common code path across either kind of resource. * allows a common code path across either kind of resource.
*/ */
if (num == 0 && has_acpi_companion(&dev->dev)) if (num == 0 && has_acpi_companion(&dev->dev)) {
return acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num); int ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
/* Our callers expect -ENXIO for missing IRQs. */
if (ret >= 0 || ret == -EPROBE_DEFER)
return ret;
}
return -ENXIO; return -ENXIO;
#endif #endif
......
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