sdhci: handle hot-remove

Gracefully handle when the device is suddenly removed. Do a test read
and avoid any further access if that read returns -1.

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

1 files changed, 16 insertions, 5 deletions

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 5dcb4958e47b..8554466e0f4e 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -47,7 +47,7 @@ struct sdhci_pci_fixes {
         int                     (*probe)(struct sdhci_pci_chip*);
 
         int                     (*probe_slot)(struct sdhci_pci_slot*);
-        void                    (*remove_slot)(struct sdhci_pci_slot*);
+        void                    (*remove_slot)(struct sdhci_pci_slot*, int);
 
         int                     (*suspend)(struct sdhci_pci_chip*,
                                         pm_message_t);
@@ -209,8 +209,11 @@ static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
         return 0;
 }
 
-static void jmicron_remove_slot(struct sdhci_pci_slot *slot)
+static void jmicron_remove_slot(struct sdhci_pci_slot *slot, int dead)
 {
+        if (dead)
+                return;
+
         if (slot->chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB38X_MMC)
                 jmicron_enable_mmc(slot->host, 0);
 }
@@ -540,7 +543,7 @@ static struct sdhci_pci_slot * __devinit sdhci_pci_probe_slot(
 
 remove:
         if (chip->fixes && chip->fixes->remove_slot)
-                chip->fixes->remove_slot(slot);
+                chip->fixes->remove_slot(slot, 0);
 
 unmap:
         iounmap(host->ioaddr);
@@ -554,10 +557,18 @@ release:
 
 static void sdhci_pci_remove_slot(struct sdhci_pci_slot *slot)
 {
-        sdhci_remove_host(slot->host);
+        int dead;
+        u32 scratch;
+
+        dead = 0;
+        scratch = readl(slot->host->ioaddr + SDHCI_INT_STATUS);
+        if (scratch == (u32)-1)
+                dead = 1;
+
+        sdhci_remove_host(slot->host, dead);
 
         if (slot->chip->fixes && slot->chip->fixes->remove_slot)
-                slot->chip->fixes->remove_slot(slot);
+                slot->chip->fixes->remove_slot(slot, dead);
 
         pci_release_region(slot->chip->pdev, slot->pci_bar);