libertas_sdio doesn't work after reloading

[Matt Reimer]

On Tue, Feb 3, 2009 at 11:44 AM, Dan Williams <dcbw at redhat.com> wrote:
> On Tue, 2009-02-03 at 14:27 -0500, Dan Williams wrote:
>> On Tue, 2009-02-03 at 11:09 -0800, Matt Reimer wrote:
>> > On Tue, Feb 3, 2009 at 7:42 AM, Dan Williams <dcbw at redhat.com> wrote:
>> > > On Tue, 2009-02-03 at 11:20 +0000, Jonathan Cameron wrote:
>> > >> Matt Reimer wrote:
>> > >> > On Mon, Feb 2, 2009 at 1:58 PM, Andrey Yurovsky <andrey at cozybit.com> wrote:
>> > >> >> Hi Matt.  Is this on an embedded system or on a desktop PC with some
>> > >> >> host controller?  If so, which one?  I'm curious because module reload
>> > >> >> seems to work fine with my Ricoh host controller.
>> > >> >
>> > >> > This is on an embedded system, using the SD controller on a pxa320.
>> > >> >
>> > >> > Matt
>> > >> >
>> > >> I ran into exactly the same issue with a pxa271 board, but never figured
>> > >> out what was going on.  Very interested to hear if you do!
>> > >
>> > > The only method I have found to reset the libertas chip is to pull the
>> > > power from the card or unplug it.  There hasn't been any other method
>> > > that we can figure out to hard-reset the card, either with SDIO commands
>> > > or with CMD_802_11_RESET.  I'd be quite interested if anyone found a
>> > > mechanism for doing a full reset while the card's plugged in.
>> >
>> > Do you think the problem could be that after reset the libertas chip
>> > is talking to the controller at the wrong bus speed and bus width?
>>
>> It could well be.  Pierre, I and Philip Rakity are having a side
>> conversation right now about this sort of thing.  Let me see if Philip
>> would mind if I pasted in his debugging patch for that.  Basically,
>> issue an SDIO ABORT/reset during MMC bus rescan.  That could kick the
>> card hard enough for it to be re-enumerated and take firmware upload
>> again.
>
> Philip's patch is below.  The mmc/core/core.c stuff doesn't apply
> directly any more, but the function getting patched is mmc_rescan() as
> far as I can tell.  Give it a shot and see if it helps you.
>
> Pierre tried something similar a while ago but noticed problems with the
> cards getting wedged because they saw the SDIO ABORT on the bus before
> being fully enumerated, or something like that.

This brings up another thought: is it possible or advisable to power
down an SDIO card when none of its functions are enabled? This would
of course save power, but would also have the side effect of making
libertas_sdio work.

Of course this wouldn't address the root cause of why we can't reset the card.

Matt