Dne 30. 09. 20 v 11:39 Takashi Iwai napsal(a):
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.
Ok, I see, the lookup is codec / nid / dev_id so in this case the multiple callback assignments are really not desired. Thanks for the explanation.
Jaroslav