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/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
index bd1d811c204f..5fedc3375562 100644
--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -247,8 +247,10 @@ static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
 }
 #endif /* CONFIG_PPC_MPC512x */
 
+static struct of_device_id mpc5xxx_can_table[];
 static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
 {
+        const struct of_device_id *match;
         struct mpc5xxx_can_data *data;
         struct device_node *np = ofdev->dev.of_node;
         struct net_device *dev;
@@ -258,9 +260,10 @@ static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
         int irq, mscan_clksrc = 0;
         int err = -ENOMEM;
 
-        if (!ofdev->dev.of_match)
+        match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
+        if (!match)
                 return -EINVAL;
-        data = (struct mpc5xxx_can_data *)ofdev->dev.of_match->data;
+        data = match->data;
 
         base = of_iomap(np, 0);
         if (!base) {