On Mon, 30 Nov 2015 17:09:33 +0100, Ville Syrjälä wrote: > > On Mon, Nov 30, 2015 at 05:24:41PM +0200, Ville Syrjälä wrote: > > On Mon, Nov 30, 2015 at 02:37:46PM +0100, Takashi Iwai wrote: > > > Implement a new i915_audio_component_ops, get_eld(). It's called by > > > the audio driver to fetch the current ELD of the given HDMI/DP port. > > > It returns the size of ELD bytes if it's valid, or zero if the audio > > > is disabled or unplugged, or a negative error code. > > > > Why do we need this? Isn't it something the eld notify hook should > > pass from i915 to the audio driver? > > > > At least with the locking you have for this, the audio driver can not > > call this from the eld notify hook since it would deadlock. > > Hmm. Actually the locking isn't perhaps quite like that atm. But I guess > the mode_config.mutex will make it so. > > Apart from that it seesm to me that you should pull the av_mutex > lock/unlock from the .audio_code_eanble/disable hooks into > intel_audio_codec_enable/disable, so that it protects the audio_enabled > flag as well. Not sure if the eld_notify should be called while holding > that lock or not. If we need to avoid calling it from the eld_notify > anywya due to other locks then maybe it can be under av_mutex as well. Currently I'm thinking of: - not allow to call get_eld directly from eld_notify; I found that the existing eld_repoll work in the HDA can be reused easily, so let's follow Daniel's advice. - drm_select_eld() seems requring mode_config.mutex and connection_mutex modeset lock in anyway; so let get_eld taking both. Is it OK to call drm_modeset_lock_all() for simplicity? - Get rid of av_mutex from get_eld instead; get_eld doesn't conflict with other ops In that way, audio_enabled flag is protected in both places via modeset lock, I suppose. thanks, Takashi _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
