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authorBrian Norris <briannorris@chromium.org>2019-07-29 23:49:54 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-30 14:46:15 +0300
commit46c42d844211ef5902e32aa507beac0817c585e9 (patch)
treed0e820be4c1f44a9514c0b323db6ae98e31bc7c4 /drivers/base
parent5f9e832c137075045d15cd6899ab0505cfb2ca4b (diff)
downloadlinux-46c42d844211ef5902e32aa507beac0817c585e9.tar.xz
driver core: platform: return -ENXIO for missing GpioInt
Commit daaef255dc96 ("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: Brian Norris <briannorris@chromium.org> Reported-by: Salvatore Bellizzi <salvatore.bellizzi@linux.seppia.net> Cc: Enrico Granata <egranata@chromium.org> Cc: <stable@vger.kernel.org> Fixes: daaef255dc96 ("driver: platform: Support parsing GpioInt 0 in platform_get_irq()") Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Enrico Granata <egranata@google.com> Link: https://lore.kernel.org/r/20190729204954.25510-1-briannorris@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/platform.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 506a0175a5a7..ec974ba9c0c4 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -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
* allows a common code path across either kind of resource.
*/
- if (num == 0 && has_acpi_companion(&dev->dev))
- return acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
+ if (num == 0 && has_acpi_companion(&dev->dev)) {
+ 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;
#endif