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/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index e2d45c91b8e8..9689d41c7888 100644
--- a/drivers/scsi/qlogicpti.c
+++ b/drivers/scsi/qlogicpti.c
@@ -1292,8 +1292,10 @@ static struct scsi_host_template qpti_template = {
         .use_clustering         = ENABLE_CLUSTERING,
 };
 
+static const struct of_device_id qpti_match[];
 static int __devinit qpti_sbus_probe(struct platform_device *op)
 {
+        const struct of_device_id *match;
         struct scsi_host_template *tpnt;
         struct device_node *dp = op->dev.of_node;
         struct Scsi_Host *host;
@@ -1301,9 +1303,10 @@ static int __devinit qpti_sbus_probe(struct platform_device *op)
         static int nqptis;
         const char *fcode;
 
-        if (!op->dev.of_match)
+        match = of_match_device(qpti_match, &op->dev);
+        if (!match)
                 return -EINVAL;
-        tpnt = op->dev.of_match->data;
+        tpnt = match->data;
 
         /* Sometimes Antares cards come up not completely
          * setup, and we get a report of a zero IRQ.