From: San Mehat <s...@google.com>
Signed-off-by: San Mehat <s...@google.com>
Signed-off-by: Bálint Czobor <czoborbal...@gmail.com>
---
drivers/mmc/core/Kconfig | 8 ++++++++
drivers/mmc/core/sd.c | 22 ++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig
index 9ebee72..1d284c1 100644
--- a/drivers/mmc/core/Kconfig
+++ b/drivers/mmc/core/Kconfig
@@ -11,3 +11,11 @@ config MMC_CLKGATE
support handling this in order for it to be of any use.
If unsure, say N.
+
+config MMC_PARANOID_SD_INIT
+ bool "Enable paranoid SD card initialization (EXPERIMENTAL)"
+ help
+ If you say Y here, the MMC layer will be extra paranoid
+ about re-trying SD init requests. This can be a useful
+ work-around for buggy controllers and hardware. Enable
+ if you are experiencing issues with SD detection.
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 4e7366a..dcbbd33 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -797,6 +797,9 @@ int mmc_sd_setup_card(struct mmc_host *host, struct
mmc_card *card,
bool reinit)
{
int err;
+#ifdef CONFIG_MMC_PARANOID_SD_INIT
+ int retries;
+#endif
if (!reinit) {
/*
@@ -823,7 +826,26 @@ int mmc_sd_setup_card(struct mmc_host *host, struct
mmc_card *card,
/*
* Fetch switch information from card.
*/
+#ifdef CONFIG_MMC_PARANOID_SD_INIT
+ for (retries = 1; retries <= 3; retries++) {
+ err = mmc_read_switch(card);
+ if (!err) {
+ if (retries > 1) {
+ printk(KERN_WARNING
+ "%s: recovered\n",
+ mmc_hostname(host));
+ }
+ break;
+ } else {
+ printk(KERN_WARNING
+ "%s: read switch failed (attempt %d)\n",
+ mmc_hostname(host), retries);
+ }
+ }
+#else
err = mmc_read_switch(card);
+#endif
+
if (err)
return err;
}
--
1.7.9.5
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