[MMC] sdhci: check controller version

Check the interface version of the controller and bail out if it's an unknown
version.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index 5324eae6d720..e37c8149249f 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -1073,6 +1073,7 @@ static int sdhci_resume (struct pci_dev *pdev)
 static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
 {
         int ret;
+        unsigned int version;
         struct sdhci_chip *chip;
         struct mmc_host *mmc;
         struct sdhci_host *host;
@@ -1131,6 +1132,16 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
                 goto release;
         }
 
+        version = readw(host->ioaddr + SDHCI_HOST_VERSION);
+        version = (version & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT;
+        if (version != 0) {
+                printk(KERN_ERR "%s: Unknown controller version (%d). "
+                        "Cowardly refusing to continue.\n", host->slot_descr,
+                        version);
+                ret = -ENODEV;
+                goto unmap;
+        }
+
         caps = readl(host->ioaddr + SDHCI_CAPABILITIES);
 
         if ((caps & SDHCI_CAN_DO_DMA) && ((pdev->class & 0x0000FF) == 0x01))