On Mon, Jul 29, 2019 at 01:49:54PM -0700, Brian Norris wrote:
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
Side note: it might have helped alleviate some of this pain if there were email notifications to the mailing list when a patch gets applied. I didn't realize (and I'm not sure if Enrico did) that v2 was already merged by the time I noted its mistakes. If I had known, I would have suggested a follow-up patch, not a v3.
I've found this to be fairly reliable for getting notified when something gets applied if it is a tree that shows up in -next.
https://www.kernel.org/get-notifications-for-your-patches.html
Cheers, Nathan