mmc: core: Bus width testing needs to handle suspend/resume

On reading the ext_csd for the first time (in 1 bit mode), save the
ext_csd information needed for bus width compare.

On every pass we make re-reading the ext_csd, compare the data
against the saved ext_csd data.

This fixes a regression introduced in 3.0-rc1 by 08ee80cc397ac1a3
("mmc: core: eMMC bus width may not work on all platforms"), which
incorrectly assumed we would be re-reading the ext_csd at resume-
time.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 63 insertions, 27 deletions

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 2a7e43bc796d..aa7d1d79b8c5 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -247,12 +247,12 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                 return 0;
 
         /* Version is coded in the CSD_STRUCTURE byte in the EXT_CSD register */
+        card->ext_csd.raw_ext_csd_structure = ext_csd[EXT_CSD_STRUCTURE];
         if (card->csd.structure == 3) {
-                int ext_csd_struct = ext_csd[EXT_CSD_STRUCTURE];
-                if (ext_csd_struct > 2) {
+                if (card->ext_csd.raw_ext_csd_structure > 2) {
                         printk(KERN_ERR "%s: unrecognised EXT_CSD structure "
                                 "version %d\n", mmc_hostname(card->host),
-                                        ext_csd_struct);
+                                        card->ext_csd.raw_ext_csd_structure);
                         err = -EINVAL;
                         goto out;
                 }
@@ -266,6 +266,10 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                 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];
+        card->ext_csd.raw_sectors[2] = ext_csd[EXT_CSD_SEC_CNT + 2];
+        card->ext_csd.raw_sectors[3] = ext_csd[EXT_CSD_SEC_CNT + 3];
         if (card->ext_csd.rev >= 2) {
                 card->ext_csd.sectors =
                         ext_csd[EXT_CSD_SEC_CNT + 0] << 0 |
@@ -277,7 +281,7 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                 if (card->ext_csd.sectors > (2u * 1024 * 1024 * 1024) / 512)
                         mmc_card_set_blockaddr(card);
         }
-
+        card->ext_csd.raw_card_type = ext_csd[EXT_CSD_CARD_TYPE];
         switch (ext_csd[EXT_CSD_CARD_TYPE] & EXT_CSD_CARD_TYPE_MASK) {
         case EXT_CSD_CARD_TYPE_DDR_52 | EXT_CSD_CARD_TYPE_52 |
              EXT_CSD_CARD_TYPE_26:
@@ -307,6 +311,11 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                         mmc_hostname(card->host));
         }
 
+        card->ext_csd.raw_s_a_timeout = ext_csd[EXT_CSD_S_A_TIMEOUT];
+        card->ext_csd.raw_erase_timeout_mult =
+                ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT];
+        card->ext_csd.raw_hc_erase_grp_size =
+                ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
         if (card->ext_csd.rev >= 3) {
                 u8 sa_shift = ext_csd[EXT_CSD_S_A_TIMEOUT];
                 card->ext_csd.part_config = ext_csd[EXT_CSD_PART_CONFIG];
@@ -334,6 +343,16 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                 card->ext_csd.boot_size = ext_csd[EXT_CSD_BOOT_MULT] << 17;
         }
 
+        card->ext_csd.raw_hc_erase_gap_size =
+                ext_csd[EXT_CSD_PARTITION_ATTRIBUTE];
+        card->ext_csd.raw_sec_trim_mult =
+                ext_csd[EXT_CSD_SEC_TRIM_MULT];
+        card->ext_csd.raw_sec_erase_mult =
+                ext_csd[EXT_CSD_SEC_ERASE_MULT];
+        card->ext_csd.raw_sec_feature_support =
+                ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT];
+        card->ext_csd.raw_trim_mult =
+                ext_csd[EXT_CSD_TRIM_MULT];
         if (card->ext_csd.rev >= 4) {
                 /*
                  * Enhanced area feature support -- check whether the eMMC
@@ -341,7 +360,7 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                  * area offset and size to user by adding sysfs interface.
                  */
                 if ((ext_csd[EXT_CSD_PARTITION_SUPPORT] & 0x2) &&
-                                (ext_csd[EXT_CSD_PARTITION_ATTRIBUTE] & 0x1)) {
+                    (ext_csd[EXT_CSD_PARTITION_ATTRIBUTE] & 0x1)) {
                         u8 hc_erase_grp_sz =
                                 ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
                         u8 hc_wp_grp_sz =
@@ -401,17 +420,17 @@ static inline void mmc_free_ext_csd(u8 *ext_csd)
 }
 
 
-static int mmc_compare_ext_csds(struct mmc_card *card, u8 *ext_csd,
-                        unsigned bus_width)
+static int mmc_compare_ext_csds(struct mmc_card *card, unsigned bus_width)
 {
         u8 *bw_ext_csd;
         int err;
 
+        if (bus_width == MMC_BUS_WIDTH_1)
+                return 0;
+
         err = mmc_get_ext_csd(card, &bw_ext_csd);
-        if (err)
-                return err;
 
-        if ((ext_csd == NULL || bw_ext_csd == NULL)) {
+        if (err || bw_ext_csd == NULL) {
                 if (bus_width != MMC_BUS_WIDTH_1)
                         err = -EINVAL;
                 goto out;
@@ -421,35 +440,40 @@ static int mmc_compare_ext_csds(struct mmc_card *card, u8 *ext_csd,
                 goto out;
 
         /* only compare read only fields */
-        err = (!(ext_csd[EXT_CSD_PARTITION_SUPPORT] ==
+        err = (!(card->ext_csd.raw_partition_support ==
                         bw_ext_csd[EXT_CSD_PARTITION_SUPPORT]) &&
-                (ext_csd[EXT_CSD_ERASED_MEM_CONT] ==
+                (card->ext_csd.raw_erased_mem_count ==
                         bw_ext_csd[EXT_CSD_ERASED_MEM_CONT]) &&
-                (ext_csd[EXT_CSD_REV] ==
+                (card->ext_csd.rev ==
                         bw_ext_csd[EXT_CSD_REV]) &&
-                (ext_csd[EXT_CSD_STRUCTURE] ==
+                (card->ext_csd.raw_ext_csd_structure ==
                         bw_ext_csd[EXT_CSD_STRUCTURE]) &&
-                (ext_csd[EXT_CSD_CARD_TYPE] ==
+                (card->ext_csd.raw_card_type ==
                         bw_ext_csd[EXT_CSD_CARD_TYPE]) &&
-                (ext_csd[EXT_CSD_S_A_TIMEOUT] ==
+                (card->ext_csd.raw_s_a_timeout ==
                         bw_ext_csd[EXT_CSD_S_A_TIMEOUT]) &&
-                (ext_csd[EXT_CSD_HC_WP_GRP_SIZE] ==
+                (card->ext_csd.raw_hc_erase_gap_size ==
                         bw_ext_csd[EXT_CSD_HC_WP_GRP_SIZE]) &&
-                (ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT] ==
+                (card->ext_csd.raw_erase_timeout_mult ==
                         bw_ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT]) &&
-                (ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] ==
+                (card->ext_csd.raw_hc_erase_grp_size ==
                         bw_ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]) &&
-                (ext_csd[EXT_CSD_SEC_TRIM_MULT] ==
+                (card->ext_csd.raw_sec_trim_mult ==
                         bw_ext_csd[EXT_CSD_SEC_TRIM_MULT]) &&
-                (ext_csd[EXT_CSD_SEC_ERASE_MULT] ==
+                (card->ext_csd.raw_sec_erase_mult ==
                         bw_ext_csd[EXT_CSD_SEC_ERASE_MULT]) &&
-                (ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT] ==
+                (card->ext_csd.raw_sec_feature_support ==
                         bw_ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT]) &&
-                (ext_csd[EXT_CSD_TRIM_MULT] ==
+                (card->ext_csd.raw_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);
+                (card->ext_csd.raw_sectors[0] ==
+                        bw_ext_csd[EXT_CSD_SEC_CNT + 0]) &&
+                (card->ext_csd.raw_sectors[1] ==
+                        bw_ext_csd[EXT_CSD_SEC_CNT + 1]) &&
+                (card->ext_csd.raw_sectors[2] ==
+                        bw_ext_csd[EXT_CSD_SEC_CNT + 2]) &&
+                (card->ext_csd.raw_sectors[3] ==
+                        bw_ext_csd[EXT_CSD_SEC_CNT + 3]));
         if (err)
                 err = -EINVAL;
 
@@ -770,7 +794,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
                                  */
                                 if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))
                                         err = mmc_compare_ext_csds(card,
-                                                ext_csd,
                                                 bus_width);
                                 else
                                         err = mmc_bus_test(card, bus_width);
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index c6927a4d157f..6ad43554ac05 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -64,6 +64,19 @@ struct mmc_ext_csd {
         unsigned long long      enhanced_area_offset;   /* Units: Byte */
         unsigned int            enhanced_area_size;     /* Units: KB */
         unsigned int            boot_size;              /* in bytes */
+        u8                      raw_partition_support;  /* 160 */
+        u8                      raw_erased_mem_count;   /* 181 */
+        u8                      raw_ext_csd_structure;  /* 194 */
+        u8                      raw_card_type;          /* 196 */
+        u8                      raw_s_a_timeout;                /* 217 */
+        u8                      raw_hc_erase_gap_size;  /* 221 */
+        u8                      raw_erase_timeout_mult; /* 223 */
+        u8                      raw_hc_erase_grp_size;  /* 224 */
+        u8                      raw_sec_trim_mult;      /* 229 */
+        u8                      raw_sec_erase_mult;     /* 230 */
+        u8                      raw_sec_feature_support;/* 231 */
+        u8                      raw_trim_mult;          /* 232 */
+        u8                      raw_sectors[4];         /* 212 - 4 bytes */
 };
 
 struct sd_scr {