From: Milton Miller Date: Wed, 18 May 2011 15:27:39 +0000 (-0500) Subject: of: fix race when matching drivers X-Git-Tag: v2.6.39~2^2~1 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=01294d82622d6d9d64bde8e4530c7e2c6dbb6ee6;p=~shefty%2Frdma-dev.git 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 Signed-off-by: Milton Miller [grant.likely: modified to only call of_match_device() once] Signed-off-by: Grant Likely --- diff --git a/include/linux/of_device.h b/include/linux/of_device.h index 8bfe6c1d436..b33d68814a7 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);