No ethernet interface found after suspend-resume

Chris Ball cjb at laptop.org
Fri Apr 30 12:10:35 EDT 2010


Hi,

   > How can i reset the card? I use a gpio - If i do a reset - The
   > firmware again gets downloaded. I need to again configure my
   > ethernet interface and get an IP address. which i dont think is
   > the right way to do.

Yes, that's what has to happen if the card loses power.  (And the card
losing power is what has to happen on vanilla 2.6.29.)

   > Can you elaborate on this? I cant upgrade to .33. I would like to
   > back port to .29.

Let me just check what you're trying to do -- you want the card to
retain power while the CPU's in suspend, and you want it to stay
associated during suspend.  Do you also want packets sent to the card
during suspend to wake up the system?  Or is it just the extra time
that it takes to bring the interface back up after suspend that you're
trying to get rid of?

Here's some of the patchset I was talking about:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=da68c4eb258cd9f3f0b8aeb7e46b8118bb6358b6
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2f4cbb3d834922ffa0309b6a08fa42dac87ef9d2
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3bca4cf703826fcb2bbabbe19c6fc7b2fc4fd7cc
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=40216842dca4fa485cb1aa5eb231149a4a57cc85
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6b5eda369ac3772dad416ef96d86064204d74770

The commits themselves try to document what's going on -- Nico's
patchset introduces an MMC_PM_KEEP_POWER flag to be set per-card,
and then allows cards with that flag set to avoid the standard
reinitialization on resume.  We use this at OLPC to allow the 8686
to wake up the host on new packets, by keeping the interface up and
sending the HOSTSLEEP command to the module in if_sdio_suspend().

- Chris.
-- 
Chris Ball   <cjb at laptop.org>
One Laptop Per Child



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