Re: Recent and not-so problems with tifm_sd driver

From: Alex Dubov
Date: Mon Feb 12 2007 - 06:54:00 EST



--- Pierre Ossman <drzeus-mmc@xxxxxxxxx> wrote:

> Alex Dubov wrote:
> >
> > It just occurred to me that my synopsis of the problem was utterly lame.
> > Here, the correct description:
> > When the card is pulled out, I mark the host as "ejected" (so it fast-fails all the requests),
> > sleep a little for it to relax and then call mmc_remove_host. Otherwise, nasty things happen.
> > Here's the example not involving mmc_block at all (command 3 failed, hardware timeout was
> missed,
> > so software timeout picked it up; the sleep hack is disabled):
> >
>
> I believe your problem is line 915 of tifm_sd.c:
>
> > tifm_set_drvdata(sock, NULL);
>
> You call that before mmc_free_host() (which flushes the work queue), and I
> assume something still needs it. Put in some BUG_ON() here and there and you
> should be able to catch it.
>
I removed that line altogether (it does not really needed as mmc host will not be accessed
anymore). The problem is more elaborate. Here, the card fails, mmc_host_remove is called without
sleep beforehand, and "after remove" message is printed immediately after it. Only then, mmc_block
remembers to finish its business. If I leave the sleep in place, mmc_block's stuff will get
scheduled before the mmc_remove_host and everything will be all right.
You may also notice that host is already powered off ("Setting ... power 0" message) and still
mmc_block continues to make requests like nothing happened.

Feb 12 22:06:55 mortug tifm_sd tifm_sd0:3: host_status 400, fifo_status 0
Feb 12 22:06:56 mortug tifm_sd: card failed to respond for a long period of time
Feb 12 22:06:56 mortug tifm_7xx1 0000:06:09.3: checking media set 8
Feb 12 22:06:56 mortug tifm_7xx1: demand removing card from socket 0:3
Feb 12 22:06:56 mortug tifm_sd tifm_sd0:3: Setting bus width 0, power 0
Feb 12 22:06:56 mortug tifm_sd tifm_sd0:3: after remove
Feb 12 22:06:56 mortug mmcblk1: error 1 sending read/write command
Feb 12 22:06:56 mortug end_request: I/O error, dev mmcblk1, sector 0
Feb 12 22:06:56 mortug printk: 137 messages suppressed.
Feb 12 22:06:56 mortug Buffer I/O error on device mmcblk1, logical block 0
Feb 12 22:06:56 mortug divide error: 0000 [1] SMP
Feb 12 22:06:56 mortug CPU 0
Feb 12 22:06:56 mortug Modules linked in: ...



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