• Hannes Reinecke's avatar
    ACPI support for IDE devices · e3a59b4d
    Hannes Reinecke authored
    This patch implements ACPI integration for generic IDE devices.
    The ACPI spec mandates that some methods are called during suspend and
    resume. And consequently there most modern Laptops cannot resume
    properly without it.
    
    According to the spec, we should call '_GTM' (Get Timing) upon suspend
    to store the current IDE adapter settings.
    Upon resume we should call '_STM' (Set Timing) to initialize the
    adapter with the stored settings; afterwards '_GTF' (Get Taskfile)
    should be called which returns a buffer with some IDE initialisation
    commands. Those commands should be passed to the drive.
    
    There are two module params which control the behaviour of this patch:
    
    'ide=noacpi'
    	Do not call any ACPI methods (Disables any ACPI method calls)
    'ide=acpigtf'
    	Enable execution of _GTF methods upon resume.
    	Has no effect if 'ide=noacpi' is set.
    'ide=acpionboot'
    	Enable execution of ACPI methods during boot.
    	This might be required on some machines if 'ide=acpigtf' is
    	selected as some machines modify the _GTF information
    	depending on the drive identification passed down with _STM.
    Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
    Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
    e3a59b4d
ide.c 56.8 KB