diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c index dc2db9c185ea..eda1e2ddcaca 100644 --- a/drivers/mmc/host/jz4740_mmc.c +++ b/drivers/mmc/host/jz4740_mmc.c @@ -1053,6 +1053,16 @@ static int jz4740_mmc_probe(struct platform_device* pdev) mmc->ops = &jz4740_mmc_ops; if (!mmc->f_max) mmc->f_max = JZ_MMC_CLK_RATE; + + /* + * There seems to be a problem with this driver on the JZ4760 and + * JZ4760B SoCs. There, when using the maximum rate supported (50 MHz), + * the communication fails with many SD cards. + * Until this bug is sorted out, limit the maximum rate to 24 MHz. + */ + if (host->version == JZ_MMC_JZ4760 && mmc->f_max > JZ_MMC_CLK_RATE) + mmc->f_max = JZ_MMC_CLK_RATE; + mmc->f_min = mmc->f_max / 128; mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;