mmc: break apart switch function

Break apart the SD switch function into one that reads the capabilities
and one that acts on them.

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

1 files changed, 41 insertions, 8 deletions

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index fb18b301502e..ae54e8eb7fea 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -183,16 +183,13 @@ static void mmc_decode_scr(struct mmc_card *card)
 }
 
 /*
- * Test if the card supports high-speed mode and, if so, switch to it.
+ * Fetches and decodes switch information
  */
-static int mmc_switch_hs(struct mmc_card *card)
+static int mmc_read_switch(struct mmc_card *card)
 {
         int err;
         u8 *status;
 
-        if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
-                return MMC_ERR_NONE;
-
         err = MMC_ERR_FAILED;
 
         status = kmalloc(64, GFP_KERNEL);
@@ -209,14 +206,43 @@ static int mmc_switch_hs(struct mmc_card *card)
                  * Card not supporting high-speed will ignore the
                  * command.
                  */
-                if (err == MMC_ERR_TIMEOUT)
-                        err = MMC_ERR_NONE;
+                err = MMC_ERR_NONE;
                 goto out;
         }
 
         if (status[13] & 0x02)
                 card->sw_caps.hs_max_dtr = 50000000;
 
+out:
+        kfree(status);
+
+        return err;
+}
+
+/*
+ * Test if the card supports high-speed mode and, if so, switch to it.
+ */
+static int mmc_switch_hs(struct mmc_card *card)
+{
+        int err;
+        u8 *status;
+
+        if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
+                return MMC_ERR_NONE;
+
+        if (card->sw_caps.hs_max_dtr == 0)
+                return MMC_ERR_NONE;
+
+        err = MMC_ERR_FAILED;
+
+        status = kmalloc(64, GFP_KERNEL);
+        if (!status) {
+                printk("%s: could not allocate a buffer for switch "
+                       "capabilities.\n",
+                        mmc_hostname(card->host));
+                return err;
+        }
+
         err = mmc_sd_switch(card, 1, 0, 1, status);
         if (err != MMC_ERR_NONE)
                 goto out;
@@ -393,7 +419,14 @@ int mmc_attach_sd(struct mmc_host *host, u32 ocr)
         mmc_decode_scr(card);
 
         /*
-         * Check if card can be switched into high-speed mode.
+         * Fetch switch information from card.
+         */
+        err = mmc_read_switch(card);
+        if (err != MMC_ERR_NONE)
+                goto free_card;
+
+        /*
+         * Attempt to change to high-speed (if supported)
          */
         err = mmc_switch_hs(card);
         if (err != MMC_ERR_NONE)