mmc: require explicit support for high-speed

The new high-speed timings are similar to each other and the old
system, but not identical. And although things "just work" most of
the time, sometimes it does not. So we need to start marking which
hosts are known to fully comply with the new timings.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 5046a16..4a73e8b 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -376,10 +376,11 @@
 {
 	struct mmc_ios *ios = &host->ios;
 
-	pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u width %u\n",
+	pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
+		"width %u timing %u\n",
 		 mmc_hostname(host), ios->clock, ios->bus_mode,
 		 ios->power_mode, ios->chip_select, ios->vdd,
-		 ios->bus_width);
+		 ios->bus_width, ios->timing);
 
 	host->ops->set_ios(host, ios);
 }
@@ -809,6 +810,7 @@
 	host->ios.chip_select = MMC_CS_DONTCARE;
 	host->ios.power_mode = MMC_POWER_UP;
 	host->ios.bus_width = MMC_BUS_WIDTH_1;
+	host->ios.timing = MMC_TIMING_LEGACY;
 	mmc_set_ios(host);
 
 	mmc_delay(1);
@@ -828,6 +830,7 @@
 	host->ios.chip_select = MMC_CS_DONTCARE;
 	host->ios.power_mode = MMC_POWER_OFF;
 	host->ios.bus_width = MMC_BUS_WIDTH_1;
+	host->ios.timing = MMC_TIMING_LEGACY;
 	mmc_set_ios(host);
 }
 
@@ -1112,46 +1115,50 @@
 			continue;
 		}
 
-		/* Activate highspeed support. */
-		cmd.opcode = MMC_SWITCH;
-		cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
-			  (EXT_CSD_HS_TIMING << 16) |
-			  (1 << 8) |
-			  EXT_CSD_CMD_SET_NORMAL;
-		cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
+		if (host->caps & MMC_CAP_MMC_HIGHSPEED) {
+			/* Activate highspeed support. */
+			cmd.opcode = MMC_SWITCH;
+			cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
+				  (EXT_CSD_HS_TIMING << 16) |
+				  (1 << 8) |
+				  EXT_CSD_CMD_SET_NORMAL;
+			cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
 
-		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
-		if (err != MMC_ERR_NONE) {
-			printk("%s: failed to switch card to mmc v4 "
-			       "high-speed mode.\n",
-			       mmc_hostname(card->host));
-			continue;
+			err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
+			if (err != MMC_ERR_NONE) {
+				printk("%s: failed to switch card to mmc v4 "
+				       "high-speed mode.\n",
+				       mmc_hostname(card->host));
+				continue;
+			}
+
+			mmc_card_set_highspeed(card);
+
+			host->ios.timing = MMC_TIMING_SD_HS;
+			mmc_set_ios(host);
 		}
 
-		mmc_card_set_highspeed(card);
-
 		/* Check for host support for wide-bus modes. */
-		if (!(host->caps & MMC_CAP_4_BIT_DATA)) {
-			continue;
+		if (host->caps & MMC_CAP_4_BIT_DATA) {
+			/* Activate 4-bit support. */
+			cmd.opcode = MMC_SWITCH;
+			cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
+				  (EXT_CSD_BUS_WIDTH << 16) |
+				  (EXT_CSD_BUS_WIDTH_4 << 8) |
+				  EXT_CSD_CMD_SET_NORMAL;
+			cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
+
+			err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
+			if (err != MMC_ERR_NONE) {
+				printk("%s: failed to switch card to "
+				       "mmc v4 4-bit bus mode.\n",
+				       mmc_hostname(card->host));
+				continue;
+			}
+
+			host->ios.bus_width = MMC_BUS_WIDTH_4;
+			mmc_set_ios(host);
 		}
-
-		/* Activate 4-bit support. */
-		cmd.opcode = MMC_SWITCH;
-		cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
-			  (EXT_CSD_BUS_WIDTH << 16) |
-			  (EXT_CSD_BUS_WIDTH_4 << 8) |
-			  EXT_CSD_CMD_SET_NORMAL;
-		cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
-
-		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
-		if (err != MMC_ERR_NONE) {
-			printk("%s: failed to switch card to "
-			       "mmc v4 4-bit bus mode.\n",
-			       mmc_hostname(card->host));
-			continue;
-		}
-
-		host->ios.bus_width = MMC_BUS_WIDTH_4;
 	}
 
 	kfree(ext_csd);
@@ -1241,6 +1248,9 @@
 	unsigned char *status;
 	struct scatterlist sg;
 
+	if (!(host->caps & MMC_CAP_SD_HIGHSPEED))
+		return;
+
 	status = kmalloc(64, GFP_KERNEL);
 	if (!status) {
 		printk(KERN_WARNING "%s: Unable to allocate buffer for "
@@ -1332,6 +1342,9 @@
 		}
 
 		mmc_card_set_highspeed(card);
+
+		host->ios.timing = MMC_TIMING_SD_HS;
+		mmc_set_ios(host);
 	}
 
 	kfree(status);