mmc: Graceful fallback for fancy features

MMC high-speed, wide bus support and SD high-speed
are functions that aren't critical for correct
operation of the card. As such, they shouldn't mark
the card as bad or dead when there is a failure
activating these features.

This is needed in particular on some really stupid
hardware (e.g. Winbond's) where not all data transfer
commands are supported.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index fb04bdd26c36f9b5a536ce381376649fb0807267..5046a1661342f2e13ac8417c14ed697163368390 100644 (file)
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -1092,7 +1092,8 @@ static void mmc_process_ext_csds(struct mmc_host *host)
                mmc_wait_for_req(host, &mrq);
 
                if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
-                       mmc_card_set_dead(card);
+                       printk("%s: unable to read EXT_CSD, performance "
+                               "might suffer.\n", mmc_hostname(card->host));
                        continue;
                }
 
@@ -1108,7 +1109,6 @@ static void mmc_process_ext_csds(struct mmc_host *host)
                        printk("%s: card is mmc v4 but doesn't support "
                               "any high-speed modes.\n",
                                mmc_hostname(card->host));
-                       mmc_card_set_bad(card);
                        continue;
                }
 
@@ -1289,7 +1289,9 @@ static void mmc_read_switch_caps(struct mmc_host *host)
                mmc_wait_for_req(host, &mrq);
 
                if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
-                       mmc_card_set_dead(card);
+                       printk("%s: unable to read switch capabilities, "
+                               "performance might suffer.\n",
+                               mmc_hostname(card->host));
                        continue;
                }
 
@@ -1321,12 +1323,8 @@ static void mmc_read_switch_caps(struct mmc_host *host)
 
                mmc_wait_for_req(host, &mrq);
 
-               if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
-                       mmc_card_set_dead(card);
-                       continue;
-               }
-
-               if ((status[16] & 0xF) != 1) {
+               if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE ||
+                       (status[16] & 0xF) != 1) {
                        printk(KERN_WARNING "%s: Problem switching card "
                                "into high-speed mode!\n",
                                mmc_hostname(host));