[U-Boot] [PATCH] OMAP MMC: Add delay before waiting for status

[Tom Rini]

On Thu, Dec 22, 2011 at 2:56 AM, Andreas Müller <schnitzeltony at gmx.de> wrote:
> Loading kernel from MMC created the following error message reproducable:
>
> | reading uImage
> | mmc_send_cmd: timedout waiting for stat!
> |
> | 2860468 bytes read
>
> Tested on overo with OMAP3530:
> * OMAP3530-GP ES3.1, CPU-OPP2, L3-165MHz, Max CPU Clock 720 mHz
>  Die ID #470e000400000000040398d31402100c
> * OMAP3530-GP ES3.1, CPU-OPP2, L3-165MHz, Max CPU Clock 600 mHz
>  Die ID #112000040000000004035c140101b011
>
> Signed-off-by: Andreas Müller <schnitzeltony at gmx.de>

OK, I'm going to NAK this as-is.  Over at
https://lists.yoctoproject.org/pipermail/meta-ti/2012-January/000316.html
Andreas has provided more details about what he saw (thread is about
someone else who hit this problem on a beagleboard xM).  I've done a
bit more poking at the other MMC drivers and it seems that the "send
the mmc command" function has anywhere from a 10ms timeout (sdhci.c)
to 1ms (omap, fsl).

Now, digging more, I see that the kernel sets the mmc timeout to 20ms
and has since the driver went in, so this is presumably a more safe
value to use.  I've updated the code to use that, have a more clear
comment and name (and some related cleanup) and I've sent some test
binaries to someone internally that's reported the problem.  I'll post
a patch and cc Andreas and Peter and see if this change also fixes the
problem (it really should, but lets be safe).

Thanks folks!

-- 
Tom