Hi Mark, On 18.12.2019 14:26, Mark Brown wrote: > On Fri, Dec 13, 2019 at 02:05:32AM +0800, Tzung-Bi Shih wrote: >> I have no enough resources to test and trace the code temporarily. >> But is it possible: >> - snd_card_new( ) succeed in snd_soc_bind_card( ), so that userspace >> can see the control > This feels like snd_card_new() is being overly enthusiastic here, I'd > expect that we might have other problems elsewhere with that. I'd not > expect userspace to see things until snd_card_register() since between > _new() and that we're in the process of building the card up. Given > this we *will* need to handle partially constructed cards after all, > unless we change the ALSA core. Takashi? I'm not sure if this is an issue about partially registered card. Here is the boot log: https://paste.debian.net/1121543/ This oops happens when udev tries to do its job. The card is earlier fully registered and advertised by alsa: [ 3.501198] ALSA device list: [ 3.501300] #0: Odroid-U3 If there are any useful logs for tracking this issue, let me know how to enable them, so I will provide more logs. > >> - code in later snd_soc_bind_card( ) decided to defer the probe >> - soc_cleanup_card_resources( ) may forget to clean the control? (not >> sure about this) > There's going to be a race condition where userspace can see the control > on the partially built card regardless of if it gets cleaned up or not. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
