Dne 27.4.2017 v 21:20 Robert Jarzmik napsal(a): > Petr Cvek <petr.cvek@xxxxxx> writes: > >> The conversion from soc_camera omitted a correct handling of the clock >> gating for a sensor. When the pxa_camera driver module was removed it >> tried to unregister clk, but this caused a similar warning: >> >> WARNING: CPU: 0 PID: 6740 at drivers/media/v4l2-core/v4l2-clk.c:278 >> v4l2_clk_unregister(): Refusing to unregister ref-counted 0-0030 clock! >> >> The clock was at time still refcounted by the sensor driver. Before >> the removing of the pxa_camera the clock must be dropped by the sensor >> driver. This should be triggered by v4l2_async_notifier_unregister() call >> which removes sensor driver module too, calls unbind() function and then >> tries to probe sensor driver again. Inside unbind() we can safely >> unregister the v4l2 clock as the sensor driver got removed. The original >> v4l2_clk_unregister() should be put inside test as the clock can be >> already unregistered from unbind(). If there was not any bound sensor >> the clock is still present. >> >> The codepath is practically a copy from the old soc_camera. The bug was >> tested with a pxa_camera+ov9640 combination during the conversion >> of the ov9640 from the soc_camera. >> >> Signed-off-by: Petr Cvek <petr.cvek@xxxxxx> > > Yeah, it's way better with this patch, especially the insmod/rmmod/insmod/rmmod > test. I will post some other bugfixes (and feature adding) for pxa_camera soon. Do you wish to be CC'd? P.S. Who is the the maintainer of pxa_camera BTW? Still Guennadi Liakhovetski? Basically pxa_camera is no longer part of the soc_camera and MAINTAINERS file does not exactly specify pxa_camera.c (I'm asking because I will send the patch for ov9640 soc_camera removal too :-D). Best regards, Petr
