leandrof/u-boot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

mmc: Skip changing bus width for MMC cards earlier than version 4.0

Browse Source 
Wider bus widths (larger than default 1 bit) appeared in MMC standard
version 4.0. So, for MMC cards of any earlier version trying to change
the bus width (including ext_csd comparison) does not make any sense.
It may work incorrectly and at least cause unnecessary timeouts.
So, just skip the entire bus width related activity for earlier versions.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Tested-by: Alexey Brodkin <abrodkin@synopsys.com>
This commit is contained in:
Andrew Gabbasov 2014-12-25 10:22:25 -06:00 committed by Pantelis Antoniou
parent bf4770731c
commit fc5b32fbf3
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/mmc/mmc.c
View File

@ -486,7 +486,7 @@ static int mmc_change_freq(struct mmc *mmc)
char cardtype;
int err;
mmc->card_caps = MMC_MODE_4BIT | MMC_MODE_8BIT;
mmc->card_caps = 0;
if (mmc_host_is_spi(mmc))
return 0;
@ -495,6 +495,8 @@ static int mmc_change_freq(struct mmc *mmc)
if (mmc->version < MMC_VERSION_4)
return 0;
mmc->card_caps |= MMC_MODE_4BIT | MMC_MODE_8BIT;
err = mmc_send_ext_csd(mmc, ext_csd);
if (err)
@ -1349,7 +1351,8 @@ static int mmc_startup(struct mmc *mmc)
mmc->tran_speed = 50000000;
else
mmc->tran_speed = 25000000;
} else {
} else if (mmc->version >= MMC_VERSION_4) {
/* Only version 4 of MMC supports wider bus widths */
int idx;
/* An array of possible bus widths in order of preference */