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>

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index fb18b30..ae54e8e 100644 (file)
--- 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)