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 <wendy.wang@xxxxxxxxx> > Tested-by: Feng Chenzhou <chenzhoux.feng@xxxxxxxxx> > Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
