[PATCH 0/3] WLAN/SDIO power up/down synchronization

Andy Green andy at openmoko.com
Sat Nov 22 09:48:09 CET 2008

Hash: SHA1

Somebody in the thread at some point said:

| It's basically that s3cmci asks the stack to remove the driver on
| suspend, and to re-insert it on resume. This causes the stack to
| try to identify the "new" card. Unfortunately, without a prior
| reset, this will fail, because the commands used for this are only
| allowed after reset.

Yes it's the same of uSD handling with the higher levels controlled by
this stack.  It sends a command to reset the card to idle during suspend
and brings the card up fresh during resume: but this is hidden from the
higher levels on the Linux side so it sees an unchanged device.

Association is presumably lost because the firmware in the Atheros
module is directly seeing this "go down", "come back up from scratch"

| That change will partially obsolete the patch set I just sent in
| the sense that the HIF will never be reached on resume, but all
| the rest of the power handling is still needed for modules.

It's fine for now, It's no worse than normal soft MAC device under Linux
where mac80211 is down in suspend and association is lost:
NetworkManager or similar will reacquire it on resume.  I don't think
many users at all (any?) right now rely on WLAN operation live in
suspend, IIUI this should at least get us over the common case of WLAN
not broken on resume so it's very good to have: thanks.

- -Andy
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