Re: mmc_spi stopped working

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From: David Brownell
Date: Wednesday, October 17, 2007 - 12:37 pm

> I just tried out mmc_spi on Linux HEAD and it no longer works. :/

I noticed that too.  I've got a patch for one bug (appended), and
will be looking at a fix for the second.



That issue is 49dce689ad4ef0fd1f970ef762168e4bd46f69a3, the
classdev-elimination patch from Tony Jones.  It broke the
"does this bus have more than one device" test by relocating
the relevant sysfs nodes.

Quick workaround for that one is to disable the fault return
after that test.

- Dave

==========	CUT HERE
When enumerating MMC cards using SPI, don't support the "just probe"
mechanism since it doesn't always work.  Instead, always wait for the
reset to complete before issuing the next request.

This is a regression ... this SanDisk MMC card used to enumerate with
no trouble, despite this particular spec violation.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

--- a/drivers/mmc/core/mmc_ops.c	2007-10-13 17:44:43.000000000 -0700
+++ b/drivers/mmc/core/mmc_ops.c	2007-10-16 18:54:38.000000000 -0700
@@ -115,8 +115,11 @@ int mmc_send_op_cond(struct mmc_host *ho
 		if (err)
 			break;
 
-		/* if we're just probing, do a single pass */
-		if (ocr == 0)
+		/* if we're just probing, do a single pass ... except,
+		 * accomodate cards which don't behave right until a
+		 * SPI reset completes.
+		 */
+		if (ocr == 0 && !mmc_host_is_spi(host))
 			break;
 
 		/* otherwise wait until reset completes */
-
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Messages in current thread:
mmc_spi stopped working, Pierre Ossman, (Wed Oct 17, 12:19 pm)
Re: mmc_spi stopped working, David Brownell, (Wed Oct 17, 12:37 pm)
Re: mmc_spi stopped working, Pierre Ossman, (Wed Oct 17, 12:52 pm)
Re: mmc_spi stopped working, Pierre Ossman, (Mon Oct 22, 11:03 am)
Re: mmc_spi stopped working, David Brownell, (Wed Oct 24, 3:27 pm)
Re: mmc_spi stopped working, David Brownell, (Wed Oct 24, 3:37 pm)
Re: mmc_spi stopped working, Pierre Ossman, (Sat Oct 27, 5:52 am)
Re: mmc_spi stopped working, Pierre Ossman, (Sat Oct 27, 6:00 am)