diff options
| author | Macpaul Lin <macpaul@andestech.com> | 2011-11-28 16:31:09 +0000 |
|---|---|---|
| committer | Andy Fleming <afleming@freescale.com> | 2012-01-08 21:28:16 -0600 |
| commit | 2c3fbf4cbe621680105c5116b37e863a32ce410d (patch) | |
| tree | 0afeb999498b0e940661ea4b34bdf97297431040 /drivers/mmc | |
| parent | 4692708d452b054fe5996405ee5cfff1f3b23070 (diff) | |
mmc: add host_caps checking avoid switch card improperly
Add a host capability checking to avoid the mmc stack
switch the card to HIGHSPEED mode when the card supports
HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the
mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin <macpaul@andestech.com>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/mmc.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ecc5b..98abf1c8e8 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0; + /* + * If the host doesn't support SD_HIGHSPEED, do not switch card to + * HIGHSPEED mode even if the card support SD_HIGHSPPED. + * This can avoid furthur problem when the card runs in different + * mode between the host. + */ + if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && + (mmc->host_caps & MMC_MODE_HS))) + return 0; + err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status); if (err) |