Hi Daniel, On Thu, Dec 19, 2013 at 09:53:14PM +0100, Daniel Lezcano wrote: > On 12/19/2013 07:32 PM, Sören Brinkmann wrote: > >Hi Daniel, > > > >On Wed, Dec 18, 2013 at 10:58:26PM +0100, Daniel Lezcano wrote: > >>On 12/18/2013 05:47 PM, Sören Brinkmann wrote: > >>>Hi Daniel, > >>> > >>>On Wed, Dec 18, 2013 at 03:53:51PM +0100, Daniel Lezcano wrote: > >>>>On 12/17/2013 08:21 PM, Sören Brinkmann wrote: > >>>>>Hi Daniel, > >>>>> > >>>>>On Tue, Nov 26, 2013 at 05:04:50PM -0800, Soren Brinkmann wrote: > >>>>>>It is not allowed to call clk_get_rate() from interrupt context. To > >>>>>>avoid such calls the timer input frequency is stored in the driver's > >>>>>>data struct which makes it accessible to the driver in any context. > >>>>>> > >>>>>>Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx> > >>>>>>Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> > >>>>> > >>>>>I doubt that we'll resolve all issues with this series before the > >>>>>holidays or even the next merge window. Could you take this patch into > >>>>>your tree for 3.14? It is not directly related to the cpufreq work and > >>>>>fixes an actual issue that triggers a kernel WARN under some condition > >>>>>(I missed preserving the details and the trace). That would take the > >>>>>easy stuff out of the way and we can focus on the more controversial > >>>>>changes. > >>>> > >>>>You are asking to take it for 3.14 but shouldn't it go as a 3.13 fix ? > >>> > >>>That's also an option. As I remember, the patch fixes a kernel WARN. The > >>>system still seemed operational though. Up to you whether this is > >>>considered severe enough for the 3.13 series. I'm happy either way. > >> > >>I was not able to reproduce the WARN with my board. > >> > >>Please, could you give the WARN or give the procedure to reproduce it ? > > > >I can't either... I thought I saw the WARN on a vanilla kernel during > >boot (IIRC, when cpuidle started). Is there any chance the timer core > >calls the timer's set_mode() from interrupt context? > >Anyway, let's drop it for now. I'll make sure to record more information > >in case it reappears. > > Finally I was able to reproduce it with the highres timers disabled, > the periodic tick system and the locks debug. > > Indeed, we are in an interrupt context (IPI) and we are calling > clk_get_rate in the the set_mode function which in turn ends up by > getting a mutex... Even if that does not hang, it is a potential > kernel crash so I will apply the patch with an updated changelog. Thanks! Kind of comforting to know that the issue I tried to fix actually exists. Sören -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
