On Thu, 12 Oct 2023 17:41:34 +0300 Péter Ujfalusi <peter.ujfalusi@xxxxxxxxx> wrote: > On 07/10/2023 10:11, Andreas Kemnade wrote: > >> OK good to hear it works, I'll send out fixes for omap4 and 5, seems > >> the runtime PM warning is something different. > >> > >>> omap-mcbsp 40124000.mcbsp: Runtime PM usage count underflow! > >>> # cat /sys/bus/platform/devices/40124000.mcbsp/power/runtime_status > >>> active > >>> > >>> even with no sound. > >> > > Well, it is a regression caused by your fix. Without it (and not reverting > > the already applied ignore patch), runtime is properly suspended. Don't know > > why yet. > > I guess it is because of the pm_runtime_put_sync() in the > omap2_mcbsp_set_clks_src() around the fclk re-parenting. > That is a bit dubious thing for sure. We need to disable the device to > be able to re-parent the fclk but if we disable the device it is going > to be powered down, right? I think we have appropriate context handling, > so it might work, but it is certainly not a rock solid code... If you > have a stream running already, you don't really want to kill the McBSP. > Ok, so if the device is powered of at omap2_mcbsp_set_clks_src() we get the usage count underflow, and the counter is incremented immediately again in the runtime put function. So things get out of balance... I'll check Tony's fix here. > The problem is that this mux is outside of the McBSP IP, so we need a > system level (iow, clk API) way to change it runtime. > > What is the machine driver where this happens? If you set the sysclk in > hw_params of the machine driver, it will be OK, but if you do that in > probe time then it is likely going to fail as you experienced > As you see in the other patches of this series, it is a simple-audio-card with a tlv320aic3x codec in combination with the mcbsp. Regards, Andreas
