diff options
| author | Milton Miller <miltonm@bga.com> | 2011-05-18 19:27:39 +0400 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2011-05-18 20:19:36 +0400 |
| commit | 01294d82622d6d9d64bde8e4530c7e2c6dbb6ee6 (patch) | |
| tree | 98707dfac7c9533dbfef30c4ff05c0dfdabc17a6 | |
| parent | 2e9521fd656f05a716b5294a7dbebd37ced05e43 (diff) | |
| download | linux-01294d82622d6d9d64bde8e4530c7e2c6dbb6ee6.tar.xz | |
of: fix race when matching drivers
If two drivers are probing devices at the same time, both will write
their match table result to the dev->of_match cache at the same time.
Only write the result if the device matches.
In a thread titled "SBus devices sometimes detected, sometimes not",
Meelis reported his SBus hme was not detected about 50% of the time.
From the debug suggested by Grant it was obvious another driver matched
some devices between the call to match the hme and the hme discovery
failling.
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Milton Miller <miltonm@bga.com>
[grant.likely: modified to only call of_match_device() once]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
| -rw-r--r-- | include/linux/of_device.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/include/linux/of_device.h b/include/linux/of_device.h index 8bfe6c1d4365..b33d68814a73 100644 --- a/include/linux/of_device.h +++ b/include/linux/of_device.h @@ -21,8 +21,12 @@ extern void of_device_make_bus_id(struct device *dev); static inline int of_driver_match_device(struct device *dev, const struct device_driver *drv) { - dev->of_match = of_match_device(drv->of_match_table, dev); - return dev->of_match != NULL; + const struct of_device_id *match; + + match = of_match_device(drv->of_match_table, dev); + if (match) + dev->of_match = match; + return match != NULL; } extern struct platform_device *of_dev_get(struct platform_device *dev); |