thinkpad-acpi: volume subdriver rewrite
commite77008c0d1c201f482dd5814dd3eb8b18182023c
authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Sat, 3 Sep 2011 18:49:18 +0000 (3 15:49 -0300)
committerHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Sun, 13 Nov 2011 17:08:31 +0000 (13 15:08 -0200)
treeaaac07b3e7584ef1fc39a5507eb7a727d5cdd7ba
parent350f6cb41bfba103222b6de79deb642f4efd2a33
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