From 66983857a54479d76ce6dbd8399e1276698bd3c5 Mon Sep 17 00:00:00 2001 From: San Mehat Date: Tue, 11 Nov 2008 09:35:36 -0800 Subject: [PATCH 094/134] mmc: sd: Add new CONFIG_MMC_PARANOID_SD_INIT for enabling retries during SD detection Signed-off-by: San Mehat --- drivers/mmc/core/Kconfig | 8 ++++++++ drivers/mmc/core/sd.c | 24 ++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 2 deletions(-) --- a/drivers/mmc/core/Kconfig +++ b/drivers/mmc/core/Kconfig @@ -14,3 +14,11 @@ config MMC_UNSAFE_RESUME This option is usually just for embedded systems which use a MMC/SD card for rootfs. Most people should say N here. +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. + --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -336,7 +336,9 @@ static int mmc_sd_init_card(struct mmc_h int err; u32 cid[4]; unsigned int max_dtr; - +#ifdef CONFIG_MMC_PARANOID_SD_INIT + int retries; +#endif BUG_ON(!host); WARN_ON(!host->claimed); @@ -439,11 +441,29 @@ static int mmc_sd_init_card(struct mmc_h err = mmc_decode_scr(card); if (err < 0) goto free_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) goto free_card; }