thinkpad-acpi: volume subdriver rewrite
commitb19ca610799cc6574b498ef322b6d5982662f19c
authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Sat, 3 Apr 2010 21:44:39 +0000 (3 18:44 -0300)
committerHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Tue, 27 Apr 2010 03:47:28 +0000 (27 00:47 -0300)
tree1b54bf5f164ca9190c52a9aa8b878834fe6a6687
parent5bf3475919c4544e2b09eacf0a608a632af756e9
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