Hi, On 02/06/2011 02:35 AM, Philip Rakity wrote: > > 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); > At least on the Nintendo Wii, a platform reset _does not_ reset the SDIO hardware, and there is no known way to power-off/power-on it. So, in some cases like after a system reboot, we need to issue a CMD52 before a CMD0 (even if on that particular case host->card is NULL) to properly reset the Nintendo Wii SDIO-based Wireless LAN card from its previous state, otherwise the card is not detected. The proposed fix breaks this and makes the card unavailable after a system reboot. If you are concerned about unconditionally issuing a CMD52 then we can use a quirk to make sure that we always perform a SDIO reset at least for the Nintendo Wii. Cheers, Albert -- 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
