Note: I cannot test test for a few days. Following Chris suggestion posting to list.
version 2 --- return -EINVAL when compare of ext_csd_fails combine two compare routines into one per suggestion from Chris. --- version 1 CMD19 -- The offical way to validate bus widths from the JEDEC spec does not work on all platforms. Some platforms that use PCI/PCIe to connect their SD controllers are known to fail. If the quirk MMC_BUS_WIDTH_TEST is not defined we try to figure out the bus width by reading the ext_csd at different bus widths and compare this against the ext_csd read in 1 bit mode. If no ext_csd is available we default to 1 bit operations. Code has been tested on mmp2 against 8 bit eMMC and Transcend 2GB card that is known to not work in 4 bit mode. The physical pins on the card are not present to support 4 bit operation. Signed-off-by: Philip Rakity <[email protected]> --- drivers/mmc/core/mmc.c | 113 +++++++++++++++++++++++++++++++++++++++++++---- 1 files changed, 103 insertions(+), 10 deletions(-) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index baab027..6db91d6 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -174,14 +174,17 @@ static int mmc_decode_csd(struct mmc_card *card) } /* - * Read and decode extended CSD. + * Read extended CSD. */ -static int mmc_read_ext_csd(struct mmc_card *card) +static int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd) { int err; u8 *ext_csd; BUG_ON(!card); + BUG_ON(!new_ext_csd); + + *new_ext_csd = NULL; if (card->csd.mmca_vsn < CSD_SPEC_VER_4) return 0; @@ -199,12 +202,15 @@ static int mmc_read_ext_csd(struct mmc_card *card) err = mmc_send_ext_csd(card, ext_csd); if (err) { + kfree(ext_csd); + *new_ext_csd = NULL; + /* If the host or the card can't do the switch, * fail more gracefully. */ if ((err != -EINVAL) && (err != -ENOSYS) && (err != -EFAULT)) - goto out; + return err; /* * High capacity cards should have this "magic" size @@ -222,9 +228,23 @@ static int mmc_read_ext_csd(struct mmc_card *card) mmc_hostname(card->host)); err = 0; } + } else + *new_ext_csd = ext_csd; - goto out; - } + return err; +} + +/* + * Decode extended CSD. + */ +static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd) +{ + int err = 0; + + BUG_ON(!card); + + if (!ext_csd) + return 0; /* Version is coded in the CSD_STRUCTURE byte in the EXT_CSD register */ if (card->csd.structure == 3) { @@ -372,8 +392,70 @@ static int mmc_read_ext_csd(struct mmc_card *card) card->erased_byte = 0x0; out: + return err; +} + +static inline void mmc_free_ext_csd(u8 *ext_csd) +{ kfree(ext_csd); +} + +static int mmc_compare_ext_csds(struct mmc_card *card, u8 *ext_csd, + unsigned bus_width) +{ + u8 *bw_ext_csd; + int err; + + err = mmc_get_ext_csd(card, &bw_ext_csd); + if (err) + return err; + + if ((ext_csd == NULL || bw_ext_csd == NULL)) { + if (bus_width != MMC_BUS_WIDTH_1) + err = -EINVAL; + goto out; + } + + if (bus_width == MMC_BUS_WIDTH_1) + goto out; + + /* only compare read only fields */ + + err = (!(ext_csd[EXT_CSD_PARTITION_SUPPORT] == + bw_ext_csd[EXT_CSD_PARTITION_SUPPORT]) && + (ext_csd[EXT_CSD_ERASED_MEM_CONT] == + bw_ext_csd[EXT_CSD_ERASED_MEM_CONT]) && + (ext_csd[EXT_CSD_REV] == + bw_ext_csd[EXT_CSD_REV]) && + (ext_csd[EXT_CSD_STRUCTURE] == + bw_ext_csd[EXT_CSD_STRUCTURE]) && + (ext_csd[EXT_CSD_CARD_TYPE] == + bw_ext_csd[EXT_CSD_CARD_TYPE]) && + (ext_csd[EXT_CSD_S_A_TIMEOUT] == + bw_ext_csd[EXT_CSD_S_A_TIMEOUT]) && + (ext_csd[EXT_CSD_HC_WP_GRP_SIZE] == + bw_ext_csd[EXT_CSD_HC_WP_GRP_SIZE]) && + (ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT] == + bw_ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT]) && + (ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] == + bw_ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]) && + (ext_csd[EXT_CSD_SEC_TRIM_MULT] == + bw_ext_csd[EXT_CSD_SEC_TRIM_MULT]) && + (ext_csd[EXT_CSD_SEC_ERASE_MULT] == + bw_ext_csd[EXT_CSD_SEC_ERASE_MULT]) && + (ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT] == + bw_ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT]) && + (ext_csd[EXT_CSD_TRIM_MULT] == + bw_ext_csd[EXT_CSD_TRIM_MULT]) && + memcmp(&ext_csd[EXT_CSD_SEC_CNT], + &bw_ext_csd[EXT_CSD_SEC_CNT], + 4) != 0); + if (err) + err = -EINVAL; + +out: + mmc_free_ext_csd(bw_ext_csd); return err; } -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
