From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan.wahren@i2se.com (Stefan Wahren) Date: Fri, 04 Apr 2014 17:25:27 +0200 Subject: MX28: leds/pwm: Using pwm driven led as heartbeat leads to kernel warning In-Reply-To: <20140404142656.GA16383@dragon> References: <53345C93.9040005@i2se.com> <533EB9AC.6040708@i2se.com> <20140404142656.GA16383@dragon> Message-ID: <533ECEE7.6090405@i2se.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Shawn, Am 04.04.2014 16:26, schrieb Shawn Guo: > On Fri, Apr 04, 2014 at 03:54:52PM +0200, Stefan Wahren wrote: >> the problem is still reproducable in Mainline 3.14.0 and gives the same >> warning message. >> Also i add linux-leds in CC. >> >> Are there any advices to narrow down the problem? >> >> Is this problem specific to i.MX28 PWM (i don't have other kind of >> hardware)? > I don't think it's specific to i.MX28 PWM. Since the .config hook of > pwm_ops will be called from interrupt context in this case, any pwm > drivers that do sleeping calls in the hook will have this problem, e.g. > the clk APIs that hold mutex like clk_prepare() and clk_get_rate() etc. > > Shawn that sounds like the problem should be easier to reproduce. Is there anything i can do to support bugfixing, beside sending the patch? Stefan