Hi,
sorry for the inconvenience this change has caused.
On 10/5/19 12:55 PM, Hans de Goede wrote:
Note ideally this seamingly unrelated change would have been made in a
separate commit, with a message explaining the what and why of this
change.
Would I have known the impact, then yes. This change was added due to
some reported instances where it seems that soc_button_array would
occasionally load on MSHW0040 before the GPIO controller was ready,
causing power and volume buttons to not work.
I guess this change may have been added to deal with -EPROBE_DEFER errors,
Correct. After a comment mentioned that gpiod_get() returning
-EPROBE_DEFER would be the proper way to detect this, I decided on this
change.
Might I suggest the following addition:
Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
---
drivers/input/misc/soc_button_array.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
index 97e3639e99d0..a0f0c977b790 100644
--- a/drivers/input/misc/soc_button_array.c
+++ b/drivers/input/misc/soc_button_array.c
@@ -92,11 +92,18 @@ soc_button_device_create(struct platform_device *pdev,
continue;
gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
- if (gpio < 0 && gpio != -ENOENT) {
- error = gpio;
- goto err_free_mem;
- } else if (!gpio_is_valid(gpio)) {
- /* Skip GPIO if not present */
+ if (!gpio_is_valid(gpio)) {
+ /*
+ * Skip GPIO if not present. Note we deliberately
+ * ignore -EPROBE_DEFER errors here. On some devices
+ * Intel is using so called virtual GPIOs which are not
+ * GPIOs at all but some way for AML code to check some
+ * random status bits without need a custom opregion.
+ * In some cases the resources table we parse points to
+ * such a virtual GPIO, since these are not real GPIOs
+ * we do not have a driver for these so they will never
+ * show up, therefor we ignore -EPROBE_DEFER.
+ */
continue;
}
@@ -429,6 +436,14 @@ static int soc_device_check_MSHW0040(struct device *dev)
dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
+ /*
+ * Explicitly check if GPIO controller is ready. This check is done here
+ * to avoid issues with virtual GPIOs on other chips, as elaborated above.
+ * We are at least expecting one GPIO pin for the power button (index 0).
+ */
+ if (soc_button_lookup_gpio(dev, 0) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
return 0;
}
--
2.23.0
