From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: [PATCH 1/2] of: fix race when matching drivers Date: Wed, 18 May 2011 13:21:00 -0600 Message-ID: <20110518192100.28986.94335.stgit@ponder> References: <20110518185751.28986.69446.stgit@ponder> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110518185751.28986.69446.stgit@ponder> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, gregkh-l3A5Bk7waGM@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Milton Miller , sparclinux-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linus Torvalds List-Id: devicetree@vger.kernel.org From: Milton Miller 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 --- 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 8bfe6c1..b33d688 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);