diff options
| -rw-r--r-- | drivers/mmc/fsl_esdhc.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 1ccc576..6827ffb 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -252,8 +252,15 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data) * Rounding up to next power of 2 * => timeout + 13 = log2(mmc->clock/4) + 1 * => timeout + 13 = fls(mmc->clock/4) + * + * However, 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. + * So, we use + * => timeout + 13 = fls(mmc->clock/2) */ - timeout = fls(mmc->clock/4); + timeout = fls(mmc->clock/2); timeout -= 13; if (timeout > 14) |