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path: root/drivers/mmc/host/jz4740_mmc.c
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Diffstat (limited to 'drivers/mmc/host/jz4740_mmc.c')
-rw-r--r--drivers/mmc/host/jz4740_mmc.c10
1 files changed, 10 insertions, 0 deletions
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;