On Thursday, August 17, 2017 4:21:04 AM CEST Lv Zheng wrote:

The following commit is bisected out to be a regression culprit:
 Commit: c712bb58d8278465b1a91f362a08f5c79ad077e4
 Subject: ACPI / EC: Add support to skip boot stage DSDT probe
However the problem is actually originated from the following commit:
 Commit: 2a5708409e4e05446eb1a89ecb48641d6fd5d5a9
 Subject: ACPI / EC: Fix a gap that ECDT EC cannot handle EC events

Commit 2a570840 introduces acpi_ec_ecdt_start(), but invokes it too early:
earlier before acpi_ec_query_init(). Thus when EC event is flagged after
boot, ec_query_wq is not valid, resulting in a kernel warning:
 [    3.580017] BUG: unable to handle kernel NULL pointer dereference at 0000000000000102
 ...
 [    4.380005] Workqueue: events acpi_ec_event_handler
 [    4.380005] task: ffff9f539790dac0 task.stack: ffffb437c0e10000
 [    4.380005] RIP: 0010:__queue_work+0x32/0x430

Normally DSDT EC should always be valid. Thus acpi_ec_ecdt_start() is
actually a no-op in most of the cases. While the commit c712bb58 skips
probing DSDT EC as boot EC when ECDT EC is valid, making this bug
surfaced.

This patch fixes this issue by invoking acpi_ec_ecdt_start() after
acpi_ec_query_init() in acpi_ec_init().

Link: https://jira01.devtools.intel.com/browse/LCK-4348
Fixes: 2a5708409e4e ("ACPI / EC: Fix a gap that ECDT EC cannot handle EC events")
Fixes: c712bb58d827 ("ACPI / EC: Add support to skip boot stage DSDT probe")
Reported-by: Wang Wendy <redacted>
Tested-by: Feng Chenzhou <redacted>
Signed-off-by: Lv Zheng <redacted>

Well, commit c712bb58d827 is a recent one, so this needs to be fixed in 4.13.

For this reason, I'm going to apply https://patchwork.kernel.org/patch/9903127/
and I will rebase my GPEs patches on top of it (they are queued up for 4.14).
Then, I'll apply the [2/2] from this series on top of that.

Thanks,
Rafael