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/fs_enet/mii-fec.c b/drivers/net/fs_enet/mii-fec.c
index 7e840d373ab3..6a2e150e75bb 100644
--- a/drivers/net/fs_enet/mii-fec.c
+++ b/drivers/net/fs_enet/mii-fec.c
@@ -101,17 +101,20 @@ static int fs_enet_fec_mii_reset(struct mii_bus *bus)
         return 0;
 }
 
+static struct of_device_id fs_enet_mdio_fec_match[];
 static int __devinit fs_enet_mdio_probe(struct platform_device *ofdev)
 {
+        const struct of_device_id *match;
         struct resource res;
         struct mii_bus *new_bus;
         struct fec_info *fec;
         int (*get_bus_freq)(struct device_node *);
         int ret = -ENOMEM, clock, speed;
 
-        if (!ofdev->dev.of_match)
+        match = of_match_device(fs_enet_mdio_fec_match, &ofdev->dev);
+        if (!match)
                 return -EINVAL;
-        get_bus_freq = ofdev->dev.of_match->data;
+        get_bus_freq = match->data;
 
         new_bus = mdiobus_alloc();
         if (!new_bus)