thinkpad-acpi: volume subdriver rewrite
commit1bd2a6ddf50820f01165cda63c2ca2bc4f99c882
authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Sun, 13 Dec 2009 19:29:13 +0000 (13 17:29 -0200)
committerHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Sun, 13 Dec 2009 19:29:13 +0000 (13 17:29 -0200)
tree33d528a9b1fdda48f85e0df1d528656931e576e4
parent40296dcf50d6d7ed4e3925cacddf2aefb95ceda0
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