According to eMMC specification, we should issue CMD1 repeatidly in
the idle state until the eMMC is ready even if the mmc_attach_mmc()
calls this function with ocr = 0. Otherwise some eMMC devices seems
to enter the inactive mode after mmc_init_card() issued CMD0 when
the eMMC device is busy.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
We can reproduce this issue if:
- we add no-sd and no-sdio property into sdhi2 node of salvator-common.dtsi,
- the renesas_sdhi driver is kernel module,
- Using a Salvator-XS board that has Samsung eMMC device,
- enter suspend and exit it,
- and then insmod renesas_sdhi_{core,internal_dmac}.ko.
After that, the following error happened and any partitions are not detected.
mmc1: error -110 whilst initialising MMC card
I tested this patch on:
- M3-N Salvator-XS with a Samsung eMMC device,
- M3-W Salvator-X with SiliconMotion eMMC device,
- and M3-W Starter Kit with Micron eMMC device.
drivers/mmc/core/mmc_ops.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index c5208fb..d068eed 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -184,11 +184,7 @@ int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
if (err)
break;
- /* if we're just probing, do a single pass */
- if (ocr == 0)
- break;
-
- /* otherwise wait until reset completes */
+ /* wait until reset completes */
if (mmc_host_is_spi(host)) {
if (!(cmd.resp[0] & R1_SPI_IDLE))
break;
@@ -200,6 +196,17 @@ int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
err = -ETIMEDOUT;
mmc_delay(10);
+
+ /*
+ * According to eMMC specification, we should issue CMD1
+ * repeatidly in the idle state until the eMMC is ready even if
+ * the mmc_attach_mmc() calls this function with ocr = 0.
+ * Otherwise some eMMC devices seem to enter the inactive mode
+ * after mmc_init_card() issued CMD0 when the eMMC device is
+ * busy.
+ */
+ if (!ocr && !mmc_host_is_spi(host))
+ cmd.arg = cmd.resp[0] | BIT(30);
}
if (rocr && !mmc_host_is_spi(host))
--
2.7.4
