[MMC] sdhci: check SDHCI base clock

A base clock value of 0 means that the driver must get the base clock through
some other means.  As we have no other way of getting it, we must abort.

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, 4 deletions

diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index 8e9100bd57ef..0d9c327a84b0 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -1030,7 +1030,14 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
         else /* XXX: Hack to get MMC layer to avoid highmem */
                 pdev->dma_mask = 0;
 
-        host->max_clk = (caps & SDHCI_CLOCK_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
+        host->max_clk =
+                (caps & SDHCI_CLOCK_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
+        if (host->max_clk == 0) {
+                printk(KERN_ERR "%s: Hardware doesn't specify base clock "
+                        "frequency.\n", host->slot_descr);
+                ret = -ENODEV;
+                goto unmap;
+        }
         host->max_clk *= 1000000;
 
         /*
@@ -1078,7 +1085,7 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
         ret = request_irq(host->irq, sdhci_irq, SA_SHIRQ,
                 host->slot_descr, host);
         if (ret)
-                goto unmap;
+                goto untasklet;
 
         sdhci_init(host);
 
@@ -1097,10 +1104,10 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
 
         return 0;
 
-unmap:
+untasklet:
         tasklet_kill(&host->card_tasklet);
         tasklet_kill(&host->finish_tasklet);
-
+unmap:
         iounmap(host->ioaddr);
 release:
         pci_release_region(pdev, host->bar);