• Lennart Poettering's avatar
    acpi,msi-laptop: Fall back to EC polling mode for MSI laptop specific EC commands · 00eb43a1
    Lennart Poettering authored
    The ACPI EC that is used in MSI laptops knows some non-standard
    commands for changing the screen brighntess and a few other things,
    which are used by the msi-laptop.c driver. Unfortunately for these
    commands no GPE events for IBF and OBF are triggered. Since nowadays
    the EC code uses the ec_intr=1 mode by default, this causes these
    operations to timeout, although they don't fail. In result, all
    operations that you can do with the msi-laptop.c driver take more or
    less 1s to complete, which is awfully slow.
    
    In one of the more recent kernels (2.6.20?) the EC subsystem has been
    revamped. With that change the EC timeout has been increased. before
    that increase the MSI EC accesses were slow -- but not *that* slow,
    hence I took notice of this limitation of the MSI EC hardware only very
    recently.
    
    The standard EC operations on the MSI EC as defined in the ACPI spec
    support GPE events properly.
    
    The following patch adds a new argume...
    00eb43a1
acpi.h 6.39 KB