From 982eba395698af848bac3be877607afee4a376f8 Mon Sep 17 00:00:00 2001 From: Romain Izard Date: Fri, 27 Jun 2014 10:51:07 +0200 Subject: [PATCH 2/2] mmc: Allow forward compatibility for eMMC As stated by the eMMC 5.0 specification, a chip should not be rejected only because of the revision stated in the EXT_CSD_REV field of the EXT_CSD register. Remove the control on this value, the control of the CSD_STRUCTURE field should be sufficient to reject future incompatible changes. Signed-off-by: Romain Izard Signed-off-by: Ulf Hansson --- drivers/mmc/core/mmc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 1ce861a..337f667 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -291,13 +291,12 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd) } } + /* + * The EXT_CSD format is meant to be forward compatible. As long + * as CSD_STRUCTURE does not change, all values for EXT_CSD_REV + * are authorized, see JEDEC JESD84-B50 section B.8. + */ card->ext_csd.rev = ext_csd[EXT_CSD_REV]; - if (card->ext_csd.rev > 7) { - pr_err("%s: unrecognised EXT_CSD revision %d\n", - mmc_hostname(card->host), card->ext_csd.rev); - err = -EINVAL; - goto out; - } card->ext_csd.raw_sectors[0] = ext_csd[EXT_CSD_SEC_CNT + 0]; card->ext_csd.raw_sectors[1] = ext_csd[EXT_CSD_SEC_CNT + 1]; -- 2.8.1