[X][D][SRU][PATCH 0/1] Fix backlight control for ASUS laptops

[Po-Hsu Lin]

BugLink: https://bugs.launchpad.net/bugs/1837117

== SRU Justification ==
Commit 78f3ac76d9e5 ("platform/x86: asus-wmi: Tell the EC the OS will
handle the display off hotkey") causes the backlight to be permanently off
on various EeePC laptop models using the eeepc-wmi driver (Asus EeePC
1015BX, Asus EeePC 1025C).

== Fix ==
* 1dd93f87 (platform/x86: asus-wmi: Only Tell EC the OS will handle
display hotkeys from asus_nb_wmi)

This patch addes a .wmi_backlight_set_devstate quirk for specific
models to make asus_wmi_set_devstate(ASUS_WMI_DEVID_BACKLIGHT, 2, NULL)
conditional.

Only X/D contain the commit that introduce this issue (78f3ac76), this
patch can be cherry-picked into D.

For X, it needs some content adjustment to add quirks only to those
models that exist in Xenial tree.

== Test ==
Test kernels could be found here:
https://people.canonical.com/~phlin/kernel/lp-1837117-eeepc/

Bug reporter has verified that this fix works as expected on X.

== Regression Potential ==
Low, quirks limited to specific ASUS laptops and by far there is no
further change to this in upstream kernel.

Hans de Goede (1):
  platform/x86: asus-wmi: Only Tell EC the OS will handle display
    hotkeys from asus_nb_wmi

 drivers/platform/x86/asus-nb-wmi.c | 4 ++++
 drivers/platform/x86/asus-wmi.c    | 2 +-
 drivers/platform/x86/asus-wmi.h    | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

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