From: San Mehat <s...@google.com>
CC: Chris Ball <c...@laptop.org>
CC: Arnd Bergmann <a...@arndb.de>
CC: Dima Zavin <d...@android.com>
Signed-off-by: San Mehat <s...@google.com>
[Add depends on EXPERIMENTAL -jstultz]
Signed-off-by: John Stultz <john.stu...@linaro.org>
---
drivers/mmc/core/Kconfig | 9 +++++++++
drivers/mmc/core/sd.c | 22 ++++++++++++++++++++++
2 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig
index ef10387..ffc671e 100644
--- a/drivers/mmc/core/Kconfig
+++ b/drivers/mmc/core/Kconfig
@@ -27,3 +27,12 @@ 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)"
+ depends on 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 6dac89f..c0f14cb 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -403,6 +403,9 @@ struct device_type sd_type = {
int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid)
{
int err;
+#ifdef CONFIG_MMC_PARANOID_SD_INIT
+ int retries;
+#endif
/*
* Since we're changing the OCR value, we seem to
@@ -482,7 +485,26 @@ 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;
}
--
1.7.3.2.146.gca209
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