thinkpad-acpi: volume subdriver rewrite
commit59d9bd5be6adb83d6c6257bd36503da6be15d3fa
authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Fri, 27 May 2011 01:50:45 +0000 (26 22:50 -0300)
committerHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Fri, 27 May 2011 01:50:45 +0000 (26 22:50 -0300)
treee0ffa20e2f6d2ef54c5d4737e11f4a599145d437
parentf9a11ede7aeb9bdcb5b2d51366401520afc555c4
thinkpad-acpi: volume subdriver rewrite

I don't trust the coupled EC writes and SMI calls the current volume
control code does very much, although it is exactly what the IBM DSDTs
seem to do (they never do more than a single step though).

Change the driver to stop issuing SMIs, and just drive the EC directly
to the desired level (DSDTs seem to confirm this will work even on
very old models like the 570 and 600e/x).

We checkpoint directly to NVRAM (this can be turned off) at
suspend/shutdown/driver unload, which from what I can see in tbp,
should also work on every ThinkPad.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Lorne Applebaum <lorne.applebaum@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Documentation/laptops/thinkpad-acpi.txt
drivers/platform/x86/thinkpad_acpi.c