All, ALSA has to make media_entity_pipeline_start() call in irq path. I am seeing warnings that the graph_mutex is unsafe irq lock as expected. We have to update MC start/stop pipeline to be irq safe for ALSA. Maybe there are other MC interfaces that need to be irq safe, but I haven't seen any problems with my limited testing. So as per options, graph_mutex could be changed to a spinlock. It looks like drivers hold this lock and it isn't abstracted to MC API. Unfortunate, this would require changes to drivers that directly hold the lock for graph walks if this mutex is changed to spinlock. e.g: drivers/media/platform/exynos4-is/fimc-isp-video.c Changes aren't complex, just that the scope isn't limited to MC API. Other ideas?? thanks, -- Shuah -- Shuah Khan Sr. Linux Kernel Developer Open Source Innovation Group Samsung Research America (Silicon Valley) shuahkh@xxxxxxxxxxxxxxx | (970) 217-8978 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
