diff options
| author | Paul Walmsley <paul@pwsan.com> | 2012-03-12 04:58:00 -0600 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2012-04-05 20:32:34 -0400 |
| commit | 3bdc9ba892d6a294d16e9e6e0c4041926aa3d58c (patch) | |
| tree | 2b1ed75a8b3b5a40c01e8f80bc45242a3c2b35f0 | |
| parent | 8c2fc8e413ecc2c96b696e28d4eb1bc6cee8dc84 (diff) | |
mmc: use really long write timeout to deal with crappy cardsmmc-fixes-for-3.4-rc2
Several people have noticed that crappy SD cards take much longer to
complete multiple block writes than the 300ms that Linux specifies.
Try to work around this by using a three second write timeout instead.
This is a generalized version of a patch from Chase Maupin
<Chase.Maupin@ti.com>, whose patch description said:
* With certain SD cards timeouts like the following have been seen
due to an improper calculation of the dto value:
mmcblk0: error -110 transferring data, sector 4126233, nr 8,
card status 0xc00
* By removing the dto calculation and setting the timeout value
to the maximum specified by the SD card specification part A2
section 2.2.15 these timeouts can be avoided.
* This change has been used by beagleboard users as well as the
Texas Instruments SDK without a negative impact.
* There are multiple discussion threads about this but the most
relevant ones are:
* http://talk.maemo.org/showthread.php?p=1000707#post1000707
* http://www.mail-archive.com/linux-omap@vger.kernel.org/msg42213.html
* Original proposal for this fix was done by Sukumar Ghoral of
Texas Instruments
* Tested using a Texas Instruments AM335x EVM
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
| -rw-r--r-- | drivers/mmc/core/core.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 14f262e9246d..7474c47b9c08 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -527,10 +527,14 @@ void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card) if (data->flags & MMC_DATA_WRITE) /* - * The limit is really 250 ms, but that is - * insufficient for some crappy cards. + * The MMC spec "It is strongly recommended + * for hosts to implement more than 500ms + * timeout value even if the card indicates + * the 250ms maximum busy length." Even the + * previous value of 300ms is known to be + * insufficient for some cards. */ - limit_us = 300000; + limit_us = 3000000; else limit_us = 100000; |