On Fri, Nov 07, 2014 at 01:11:13PM +0000, Damien Lespiau wrote: > On Tue, Sep 16, 2014 at 04:19:07PM +0300, Imre Deak wrote: > > This patch needs to be rebased on the recent PPS changes at least > > getting/putting the AUX power domain in pps_lock()/pps_unlock() too. > > Also it should be squashed into 69/89. Some more comments below. > > Hum, do we really need to hold a reference to the AUX power in > pps_lock(), it doesn't seem that the PPS hw should a specific dependency > on the AUX power domain. We might as well just get the "port" power > domain if that's enough. pps_lock() doesn't *really* need any power domain references. The thing is that the VLV/CHV display power well hooks need to reset the pps_pipe assignment which means they should grab pps_mutex. However the vdd code can grab power domain references while already holding pps_mutex, which gets us into a neat locking inversion with the power domain mutex. The workaround I did was to grab the power domain references always around pps_mutex, so that we dodge the problem. A better solution would be to never grab power domain references while already holding pps_mutex, but I wasn't happy with how the code started to look when I tried that. But I would welcome any efforts to make that happen since the current trick is rather hackish. Also the code is now otherwise cleaner than what it was when I tried to do that, so maybe it's easier now. -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
