From 7198f3c9b13c7aa1e5d9f7ff74c0ea303174feff Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 23 Mar 2010 13:35:40 -0700 Subject: [PATCH] mmc: fix incorrect interpretation of card type bits In the extended CSD register the CARD_TYPE is an 8-bit value of which the upper 6 bits were reserved in JEDEC specifications prior to version 4.4. In version 4.4 two of the reserved bits were designated for identifying support for the newly added High-Speed Dual Data Rate. Unfortunately the mmc_read_ext_csd() function required that the reserved bits be zero instead of ignoring them as it should. This patch makes mmc_read_ext_csd() ignore the CARD_TYPE bits that are reserved or not yet supported. It also stops the function jumping to the end as though an error occurred, when it is only warns that the CARD_TYPE bits (that it does interpret) are invalid. Signed-off-by: Adrian Hunter Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/mmc/core/mmc.c | 3 +-- include/linux/mmc/mmc.h | 1 + 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 0eac6c814904..e041c003db22 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -225,7 +225,7 @@ static int mmc_read_ext_csd(struct mmc_card *card) mmc_card_set_blockaddr(card); } - switch (ext_csd[EXT_CSD_CARD_TYPE]) { + switch (ext_csd[EXT_CSD_CARD_TYPE] & EXT_CSD_CARD_TYPE_MASK) { case EXT_CSD_CARD_TYPE_52 | EXT_CSD_CARD_TYPE_26: card->ext_csd.hs_max_dtr = 52000000; break; @@ -237,7 +237,6 @@ static int mmc_read_ext_csd(struct mmc_card *card) printk(KERN_WARNING "%s: card is mmc v4 but doesn't " "support any high-speed modes.\n", mmc_hostname(card->host)); - goto out; } if (card->ext_csd.rev >= 3) { diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h index c02c8db73701..8a49cbf0376d 100644 --- a/include/linux/mmc/mmc.h +++ b/include/linux/mmc/mmc.h @@ -268,6 +268,7 @@ struct _mmc_csd { #define EXT_CSD_CARD_TYPE_26 (1<<0) /* Card can run at 26MHz */ #define EXT_CSD_CARD_TYPE_52 (1<<1) /* Card can run at 52MHz */ +#define EXT_CSD_CARD_TYPE_MASK 0x3 /* Mask out reserved and DDR bits */ #define EXT_CSD_BUS_WIDTH_1 0 /* Card is in 1 bit mode */ #define EXT_CSD_BUS_WIDTH_4 1 /* Card is in 4 bit mode */ -- 2.20.1