[PATCH] ASoC: meson: cards: select SND_DYNAMIC_MINORS
Amlogic sound cards do create a lot of pcm interfaces, possibly more than 8. Some pcm interfaces are internal (like DPCM backends and c2c) and not exposed to userspace.
Those interfaces still increase the number passed to snd_find_free_minor(), which eventually exceeds 8 causing -EBUSY error on card registration if CONFIG_SND_DYNAMIC_MINORS=n and the interface is exposed to userspace.
select CONFIG_SND_DYNAMIC_MINORS for Amlogic cards to avoid the problem.
Fixes: 7864a79f37b5 ("ASoC: meson: add axg sound card support") Signed-off-by: Jerome Brunet jbrunet@baylibre.com ---
NOTE: This problem was found while toying with a minimal configuration which disabled CONFIG_SND_DYNAMIC_MINORS and DT overlays. Overlays prepend nodes instead of doing append. This changes the order in which the links are parsed by the card driver, which in turn changes the pcm numbers. The userpace pcm number then got over 8 triggering the problem.
sound/soc/meson/Kconfig | 1 + 1 file changed, 1 insertion(+)
diff --git a/sound/soc/meson/Kconfig b/sound/soc/meson/Kconfig index b93ea33739f2..6458d5dc4902 100644 --- a/sound/soc/meson/Kconfig +++ b/sound/soc/meson/Kconfig @@ -99,6 +99,7 @@ config SND_MESON_AXG_PDM
config SND_MESON_CARD_UTILS tristate + select SND_DYNAMIC_MINORS
config SND_MESON_CODEC_GLUE tristate
On Fri, 26 Apr 2024 15:41:47 +0200, Jerome Brunet wrote:
Amlogic sound cards do create a lot of pcm interfaces, possibly more than 8. Some pcm interfaces are internal (like DPCM backends and c2c) and not exposed to userspace.
Those interfaces still increase the number passed to snd_find_free_minor(), which eventually exceeds 8 causing -EBUSY error on card registration if CONFIG_SND_DYNAMIC_MINORS=n and the interface is exposed to userspace.
[...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
Thanks!
[1/1] ASoC: meson: cards: select SND_DYNAMIC_MINORS commit: 6db26f9ea4edd8a17d39ab3c20111e3ccd704aef
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
participants (2)
-
Jerome Brunet -
Mark Brown