[PATCH] PM: HIBERNATION: add resume_wait param to support MMC-like devices as resume file

[Pavel Machek]

> 2011/9/29 Luca Tettamanti <kronos.it at gmail.com>:
> > On Thu, Sep 29, 2011 at 11:29 AM, Barry Song <Barry.Song at csr.com> wrote:
> >> From: Barry Song <baohua.song at csr.com>
> >>
> >> Some devices like mmc are async detected very slow. For example,
> >> drivers/mmc/host/sdhci.c launchs a 200ms delayed work to detect
> >> mmc partitions then add disk.
> >>
> >> we do have wait_for_device_probe and scsi_complete_async_scans
> >> before calling swsusp_check, but it is not enough to wait mmc.
> >>
> >> This patch adds resumewait kernel param just like rootwait so
> >> that we have enough time to wait mmc ready. The differene is
> >> here we wait for resume partition but rootwait waits for rootfs
> >> partition.
> >
> > I assume that such a device would need "rootwait" to boot in the first
> > place; why don't you "overload" the param to also enable waiting in
> > the resume path?
> 
> not real. for an embedded product, the type of the rootfs, the place
> of the rootfs  and the way to mount rootfs are pretty flexible.
> even though both rootfs and resume file use mmc, they will be in
> different partitions at least. so i don't think rootwait can overload
> resumewait.

It would be good to at least model it the same way. rootdelay allows
you to specify time, which is important for USB devices...

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