This is a note to let you know that I've just added the patch titled
driver core: platform: return -ENXIO for missing GpioInt
to my driver-core git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
in the driver-core-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 46c42d844211ef5902e32aa507beac0817c585e9 Mon Sep 17 00:00:00 2001
From: Brian Norris <briannorris@xxxxxxxxxxxx>
Date: Mon, 29 Jul 2019 13:49:54 -0700
Subject: 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@xxxxxxxxxx/
but apparently the patch had already been merged before v3 got sent out:
https://lore.kernel.org/lkml/20190221193429.161300-1-egranata@xxxxxxxxxxxx/
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@xxxxxxxxxxxx>
Reported-by: Salvatore Bellizzi <salvatore.bellizzi@xxxxxxxxxxxxxxxx>
Cc: Enrico Granata <egranata@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: daaef255dc96 ("driver: platform: Support parsing GpioInt 0 in platform_get_irq()")
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Acked-by: Enrico Granata <egranata@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20190729204954.25510-1-briannorris@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/platform.c | 9 +++++++--
1 file 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
--
2.22.0
