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/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 0e8eec516df4..c911b2419abb 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -80,14 +80,17 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 /*
  * Try to register a serial port
  */
+static struct of_device_id of_platform_serial_table[];
 static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
 {
+        const struct of_device_id *match;
         struct of_serial_info *info;
         struct uart_port port;
         int port_type;
         int ret;
 
-        if (!ofdev->dev.of_match)
+        match = of_match_device(of_platform_serial_table, &ofdev->dev);
+        if (!match)
                 return -EINVAL;
 
         if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
@@ -97,7 +100,7 @@ static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
         if (info == NULL)
                 return -ENOMEM;
 
-        port_type = (unsigned long)ofdev->dev.of_match->data;
+        port_type = (unsigned long)match->data;
         ret = of_platform_serial_setup(ofdev, port_type, &port);
         if (ret)
                 goto out;