On Wed, 30 Sep 2020 11:28:59 +0200, Jaroslav Kysela wrote: > > Dne 30. 09. 20 v 11:21 Takashi Iwai napsal(a): > > On Wed, 30 Sep 2020 09:19:50 +0200, > > Jaroslav Kysela wrote: > >> > >> Dne 30. 09. 20 v 7:51 Hui Wang napsal(a): > >>> If the caller of enable_callback_mst() passes a cb func, the callee > >>> function will malloc memory and link this cb func to the list > >>> unconditionally. This will introduce problem if caller is in the > >>> hda_codec_ops.init() since the init() will be repeatedly called in the > >>> codec rt_resume(). > >>> > >>> So far, the patch_hdmi.c and patch_ca0132.c call enable_callback_mst() > >>> in the hda_codec_ops.init(). > >> > >> Won't be better to handle this double invocation at the callback call time? I > >> believe that some refcounting and pointing to one allocated callback structure > >> for all instances is better. > > > > IMO, Hui's fix is correct in this case; otherwise it'll result in > > endless number of allocations at each time the runtime resume is > > performed. So I'm going to take it as is. > > I meant to allocate the structure only once with refcounting and multiple > invocation protection. In the proposed change, you lose the > bindings. AFAIUC, it won't lose any functionality. snd_hda_jack_detect_enable_callback() would chain the callback function if a jack object has been already created, and this additional check will just prevent the doubly registration of the very same callback when called multiple times. thanks, Takashi
