Messages in this thread Patch in this message | | | From | Bálint Czobor <> | Subject | [PATCH 1/3] mmc: sd: Add new CONFIG_MMC_PARANOID_SD_INIT for enabling retries during SD detection | Date | Tue, 27 Oct 2015 09:55:07 +0100 |
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From: San Mehat <san@google.com>
Signed-off-by: San Mehat <san@google.com> Signed-off-by: Bálint Czobor <czoborbalint@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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