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

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On 2/3/06, Randy.Dunlap <rdunlap@xenotime.net> wrote:
> On Fri, 3 Feb 2006, Bartlomiej Zolnierkiewicz wrote:
>
> > On 2/3/06, Randy.Dunlap <rdunlap@xenotime.net> wrote:
> > > On Fri, 3 Feb 2006, Bartlomiej Zolnierkiewicz wrote:
> > >
> > > > On 2/3/06, Matthew Garrett <mgarrett@chiark.greenend.org.uk> wrote:
> > > > > Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> 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.
> > > >
> > > > I don't see anything that prevents addition of ->suspend and ->resume
> > > > for IDE PCI host drivers (not IDE core issue) if some special sequence
> > > > is needed.
> > > >
> > > > I see that we may be doing PIO/DMA setup too late (IDE core issue)
> > > > for some controllers.
> > > >
> > > > Could you fill a bug at kernel bugzilla with data as much data about
> > > > affected hardware as possible (dmesg, kernel config, lspci -vvv -xxx
> > > > before susped and if possible PCI configuration dumped from kernel
> > > > after suspend)?
> > > >
> > > > What is the current state of IDE ACPI patches?
> > > > Were the issues raised on linux-ide addressed?
> > >
> > > I haven't seen any updates to the drivers/ide/ patch from
> > > Shaohua Li <shaohua.li@intel.com>.  I'm beginning to work on
> > > PATA ACPI object support that is similar to the current SATA ACPI
> > > patches -- all for libata.  Is this the right or wrong thing
> > > to do?
> >
> > Working on patches is always right thing to do... 8)
>
> Of course.  That wasn't really the question.  8;)
>
> > Just one remark: please try to make ACPI part
> > as libata/SCSI independent as possible.
>
> You sort of replied obliquely to my "all for libata" comment.
> These patches are all libata-specific.

Yes, developing for libata-only should be much easier to do.
We can backport it to IDE if/when needed later.

Just a reminder so nobody gets a wrong idea:
the above is in perfect harmony with my opinion wrt libata
PATA support - IDE driver should evolve and be merged
with libata (evolutionary vs revolutionary).

> At least they are SCSI-independent.  :)

Well at least not directly. :)

Bartlomiej
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