On Wed, 16 May 2018 00:22:40 +0200, Tzung-Bi Shih wrote: > > We noticed the issue because in some rarely case the code will be executed > by worker of workqueue (i.e. deferral probe since v3.4) instead of udevd. > As a result, applications rely on the change uevent of sound card (fired > from 78-sound-card.rules) will be signaled prematurely. The applications > assume when they receive the signal, everything of the sound card should be > ready. But in the case, they are still initializing. > > We have tried to change the order of SNDRV_DEV_CONTROL to the last one to > fix the bug we met and it was doing great. So if there will not bring any > side effect, it should be fine to apply the patch. The register and disconnect should be OK, as they are merely the parts to expose to and hide from user-space. > By the way, out of curiosity, prior to the commit 289ca025ee1d, it seems > the list is merely a FIFO. How to ensure control device is the last one to > register at that time? It's just the fact that snd_ctl_new() is called inside the snd_card_new(), i.e. it's the very first one to be added. If the patch works for you, please give your tested-by tag, so that I'll merge it to for-next branch. It looks like a too intrusive change for 4.17-rc6, so maybe safer to queue for 4.18. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
