ACK/Cmnt: [PATCH 0/4][SRU][Focal] fix ACPI EC initisation failures

[Stefan Bader]

On 28.09.20 21:14, Alex Hung wrote:
> BugLink: https://bugs.launchpad.net/bugs/1896482
> 
> [Impact]
> 
> The bug causes the EC driver to fail and ACPI events are no longer
> handled by Linux kernel, i.e lid close no longer triggers suspends.
> 
> [Fix]
> 
> Upstream commit 03e9a0e05739cf reworks ec_install_handlers to avoid
> initialisation failures.
> 
> The other three patches are prerequisite to apply 03e9a0e05739cf on
> focal kernel.
> 
> [Test]
> 
> Tested with Lenovo ThinkPad X1 Carbon Gen 8
> 
> [Regression Potential]
> 
> Low. The patches were cherry-picked from mainline kernel (two since 5.5
> and two since 5.7)

This is not really what regression potential should be about[1]. And beside of
that, my experience with any changes to EC code is that there is never a low
chance of something going wrong.

From what I understand, all HW with general purpose events would not be handled
differently. Assume this is the majority or is that changed by now. For the
reduced HW platforms, how could potential problems look like? Could you imagine
something to be worse off if acquiring the gpio interrupt fails? Sounds like the
last patch mitigates that by always falling back to polling. Which probably
cannot do special keys but other things...

[1] https://wiki.ubuntu.com/StableReleaseUpdates/#SRU_Bug_Template
> 
> Daniel Drake (2):
>   ACPI: EC: tweak naming in preparation for GpioInt support
>   ACPI: EC: add support for hardware-reduced systems
> 
> Rafael J. Wysocki (2):
>   ACPI: EC: Avoid passing redundant argument to functions
>   ACPI: EC: Consolidate event handler installation code
> 
>  drivers/acpi/ec.c       | 218 +++++++++++++++++++++++++++++++++---------------
>  drivers/acpi/internal.h |   3 +-
>  2 files changed, 154 insertions(+), 67 deletions(-)
> 
Acked-by: Stefan Bader <stefan.bader at canonical.com>

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20200929/9ddf5e04/attachment.sig>