proposed solution: I cannot verify this fix until Monday. ===== CMD52 is a reset for SDIO cards. CMD0 is not sufficient when the card is being re-initialized. Only send CMD52 if a) doing a reinitialize b) card is SDIO or SDIO_COMBO Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx> --- drivers/mmc/core/core.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 30d4da4..f0ce6f6 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1521,7 +1521,12 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq) mmc_hostname(host), __func__, host->f_init); #endif mmc_power_up(host); - sdio_reset(host); + + /* reset sdio before CMD0 when card is being reinitialized */ + if (host->card && + (host->card->type == MMC_TYPE_SDIO || + host->card->type == MMC_TYPE_SD_COMBO)) + sdio_reset(host); mmc_go_idle(host); mmc_hwungate_clock(host); -- 1.7.0.4 On Feb 5, 2011, at 5:15 PM, Chris Ball wrote: > On Sat, Feb 05, 2011 at 04:52:12PM -0800, Philip Rakity wrote: >> nothing negative but reset is meant to reinit the card. This is the power up sequence for the 1st time a card is detected. >> There is no reason to do this if no card has yet enumerated. If a sdio card was there I completely agree with the mod since we need to reset >> the card. >> >> CMD0 should be the 1st command on an initial power up sequence. Does my code suggestion work for you ? > > Okay -- yes, looks fine. Let's add a comment beforehand; something like: > > /* If reinitalizing, we must send CMD52 before CMD0 for SDIO. */ > > -- > Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/> > One Laptop Per Child -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
