Re: [ 00/10] [Suspend2] Modules support.

[Matthew Garrett]

Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> wrote:

> This is untrue as Linux has support for setting IDE controller
> and drives.  It was added by Benjamin Herrenschmidt in late
> 2.5.x or early 2.6.x (I don't remember exact kernel version).

In generic_ide_resume, rqpm.pm_step gets set to
ide_pm_state_start_resume and ide_do_drive_cmd gets called. This ends up
being passed through to start_request. start_request waits for the BSY
bit to go away. On the affected hardware I've seen, this never happens
unless the ACPI calls are made. As far as I can tell, there's nothing in
the current driver code that does anything to make sure that the bus is
in a state to accept commands at this point - the pci drivers don't (for
the most part) seem to have any resume methods. Calling the ACPI _STM
method before attempting to do this magically makes everything work.
-- 
Matthew Garrett | mjg59-chiark.mail.linux-rutgers.kernel@xxxxxxxxxxxxx
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