drivercore: revert addition of of_match to struct device

Commit b826291c, "drivercore/dt: add a match table pointer to struct
device" added an of_match pointer to struct device to cache the
of_match_table entry discovered at driver match time.  This was unsafe
because matching is not an atomic operation with probing a driver.  If
two or more drivers are attempted to be matched to a driver at the
same time, then the cached matching entry pointer could get
overwritten.

This patch reverts the of_match cache pointer and reworks all users to
call of_match_device() directly instead.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/mmc/host/sdhci-of-core.c b/drivers/mmc/host/sdhci-of-core.c
index f9b611fc773e..60e4186a4345 100644
--- a/drivers/mmc/host/sdhci-of-core.c
+++ b/drivers/mmc/host/sdhci-of-core.c
@@ -124,8 +124,10 @@ static bool __devinit sdhci_of_wp_inverted(struct device_node *np)
 #endif
 }
 
+static const struct of_device_id sdhci_of_match[];
 static int __devinit sdhci_of_probe(struct platform_device *ofdev)
 {
+        const struct of_device_id *match;
         struct device_node *np = ofdev->dev.of_node;
         struct sdhci_of_data *sdhci_of_data;
         struct sdhci_host *host;
@@ -134,9 +136,10 @@ static int __devinit sdhci_of_probe(struct platform_device *ofdev)
         int size;
         int ret;
 
-        if (!ofdev->dev.of_match)
+        match = of_match_device(sdhci_of_match, &ofdev->dev);
+        if (!match)
                 return -EINVAL;
-        sdhci_of_data = ofdev->dev.of_match->data;
+        sdhci_of_data = match->data;
 
         if (!of_device_is_available(np))
                 return -ENODEV;