On 2024-04-17 10:45, Felix Qin wrote:
Extensive testing has shown that a few specific SD cards require
an increase in the number of command retries to successfully
initialize.
More info:
Platform: Rockchip SoC + DW Multimedia host Controller
SD card: Xvv microSD CMH34A17TMA12 (Made in Korea)
Note: The SD card is custom-made by the customer in collaboration
with the wafer foundry.
Signed-off-by: Felix Qin <xiaokeqinhealth@xxxxxxx>
Acked-by: Avri Altman <avri.altman@xxxxxxx>
Looking good to me. Thanks for including the additional details.
Reviewed-by: Dragan Simic <dsimic@xxxxxxxxxxx>
---
v2: Add more info
---
---
drivers/mmc/core/sd_ops.c | 4 ++--
drivers/mmc/core/sd_ops.h | 8 ++++++++
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c
index a59cd592f06e..b3b6e8725b80 100644
--- a/drivers/mmc/core/sd_ops.c
+++ b/drivers/mmc/core/sd_ops.c
@@ -127,7 +127,7 @@ int mmc_send_app_op_cond(struct mmc_host *host,
u32 ocr, u32 *rocr)
cmd.arg = ocr;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;
- for (i = 100; i; i--) {
+ for (i = SD_APP_OP_COND_RETRIES; i; i--) {
err = mmc_wait_for_app_cmd(host, NULL, &cmd);
if (err)
break;
@@ -147,7 +147,7 @@ int mmc_send_app_op_cond(struct mmc_host *host,
u32 ocr, u32 *rocr)
err = -ETIMEDOUT;
- mmc_delay(10);
+ mmc_delay(SD_APP_OP_COND_INTERVAL);
}
if (!i)
diff --git a/drivers/mmc/core/sd_ops.h b/drivers/mmc/core/sd_ops.h
index 7667fc223b74..80c5c836ccd1 100644
--- a/drivers/mmc/core/sd_ops.h
+++ b/drivers/mmc/core/sd_ops.h
@@ -10,6 +10,14 @@
#include <linux/types.h>
+/*
+ * Extensive testing has shown that a few specific SD cards require
+ * an increase in the number of command retries to successfully
+ * initialize.
+ */
+#define SD_APP_OP_COND_RETRIES 200
+#define SD_APP_OP_COND_INTERVAL 10 /* millisecond */
+
struct mmc_card;
struct mmc_host;
