[PATCH 0/2][SRU][xenial] Power button fails to work on some Dell laptops

Alex Hung alex.hung at canonical.com
Mon Jun 12 05:59:48 UTC 2017

On Sun, Jun 11, 2017 at 10:21 PM, Stefan Bader
<stefan.bader at canonical.com> wrote:
> On 10.06.2017 02:34, Alex Hung wrote:
>> Impact:
>>   Some new Dell laptops use so-call 5 button array in intel-hid acpi device
>>   for external buttons such as power button and volume up/down.
>> Fix:
>>   This first patch is for conflicts, and the second patch adds the actual
>>   implementation for 5 button array.
>>   The patches are included in upstream and are cherry-picked from Linus's repo.
>> Tested:
>>   The patches are tested on Dell Latitude 7480
> The bug report is missing SRU information (similar to above but a bit more about
> risk assessment (what are the chances of regression on a laptop using intel-hid
> but not 5 button array?).

The chances should be very low.

1. The patch checks capability bit first.
2. It needs to call a newly introduced ACPI control method to enable
firmware to trigger events
3. It uses different notification numbers, from 0xC2 to 0xCF, and the
original notify handler only accepts 0xC0.

Even if BIOS reports 1 & 2 are true without supporting 5 button array,
kernel will ignore the events with some kernel messages only.

PS. When I submitted this patch to upstream, I also tested this patch
on an older system that does not support 5 button array, and I did not
see any regression and it works as expected.

> -Stefan
>> BugLink: http://bugs.launchpad.net/bugs/1697116
>> Alex Hung (2):
>>   intel-hid: Remove duplicated acpi_remove_notify_handler
>>   platform/x86: intel-hid: Support 5 button array
>>  drivers/platform/x86/intel-hid.c | 99 +++++++++++++++++++++++++++++++++++++---
>>  1 file changed, 92 insertions(+), 7 deletions(-)

Alex Hung

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