kernel/linux.git/include/sound/core.h, branch v7.1-rc5

ALSA: control: Verify put() result when in debug mode

2026-02-28T08:32:39+00:00

The put() operation is expected to return: 1) 0 on success if no changes were made 2) 1 on success if changes were made 3) error code otherwise Currently 2) is usually ignored when writing control-operations. While forcing compliance is not an option right now, make it easier for developers to adhere to the expectations and notice problems by logging them when CONFIG_SND_CTL_DEBUG is enabled. Due to large size of struct snd_ctl_elem_value, 'value_buf' is provided as a reusable buffer for kctl->put() verification. This prevents exhausting the stack when verifying the operation. >From user perspective, patch introduces a new trace/events category 'snd_ctl' containing a single 'snd_ctl_put' event type. Log sample: amixer-1086 [003] ..... 8.035939: snd_ctl_put: success: expected=0, actual=0 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0 amixer-1087 [003] ..... 8.938721: snd_ctl_put: success: expected=1, actual=1 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0 amixer-1088 [003] ..... 9.631470: snd_ctl_put: success: expected=1, actual=1 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0 amixer-1089 [000] ..... 9.636786: snd_ctl_put: fail: expected=1, actual=0 for ctl numid=5, iface=MIXER, name='Loopback Mute', index=0, device=0, subdevice=0, card=0 Signed-off-by: Cezary Rojewski Reviewed-by: Mark Brown Reviewed-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20260224205619.584795-1-cezary.rojewski@intel.com

ALSA: core: Remove unused snd_device_get_state

2025-05-05T10:36:29+00:00

snd_device_get_state() last use was removed in 2022 by commit 7e1afce5866e ("ALSA: usb-audio: Inform the delayed registration more properly") Remove it. Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20250502235219.1000429-5-linux@treblig.org

Merge branch 'topic/control-lookup-rwlock' into for-next

2024-08-09T12:25:24+00:00

Pull control lookup optimization changes. Signed-off-by: Takashi Iwai

ALSA: control: Optimize locking for look-up

2024-08-09T12:24:55+00:00

For a fast look-up of a control element via either numid or name matching (enabled via CONFIG_SND_CTL_FAST_LOOKUP), a locking isn't needed at all thanks to Xarray. OTOH, the locking is still needed for a slow linked-list traversal, and that's rather a rare case. In this patch, we reduce the use of locking at snd_ctl_find_*() API functions, and switch from controls_rwsem to controls_rwlock for avoiding unnecessary lock inversions. This also resulted in a nice cleanup, as *_unlocked() version of snd_ctl_find_*() APIs can be dropped. snd_ctl_find_id_mixer_unlocked() is still left just as an alias of snd_ctl_find_id_mixer(), since soc-card.c has a wrapper and there are several users. Once after converting there, we can remove it later. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240809104234.8488-3-tiwai@suse.de

ALSA: control: Rename ctl_files_rwlock to controls_rwlock

2024-08-09T12:24:55+00:00

We'll re-use the existing rwlock for the protection of control list lookup, too, and now rename it to a more generic name. This is a preliminary change, only the rename of the struct field here, no functional changes. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240809104234.8488-2-tiwai@suse.de

ALSA: core: Drop snd_print stuff and co

2024-08-08T05:49:47+00:00

Now that all users of snd_print*() are gone, let's drop the functions completely. This also makes CONFIG_SND_VERBOSE_PRINTK redundant, and it's dropped, too. Reviewed-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240807133452.9424-55-tiwai@suse.de

ALSA: core: Drop snd_device_initialize()

2023-08-17T07:24:33+00:00

Now all users of snd_device_intialize() are gone, let's drop it. Reviewed-by: Jaroslav Kysela Signed-off-by: Curtis Malainey Tested-by: Curtis Malainey Link: https://lore.kernel.org/r/20230816160252.23396-10-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: control: Don't embed ctl_dev

2023-08-17T07:23:30+00:00

Embedding the ctl_dev in the snd_card object may result in UAF when the delayed kobj release is used; at the delayed kobj release, it still accesses the struct device itself while the card memory (that embeds the struct device) may be already gone. As a workaround, detach the struct device from the card object by allocating via the new snd_device_alloc() helper. The rest are just replacing ctl_dev access to the pointer. This is based on the fix Curtis posted initially. In this patch, the changes are split and use the new helper function instead. Link: https://lore.kernel.org/r/20230801171928.1460120-1-cujomalainey@chromium.org Reviewed-by: Jaroslav Kysela Signed-off-by: Curtis Malainey Tested-by: Curtis Malainey Link: https://lore.kernel.org/r/20230816160252.23396-3-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: core: Introduce snd_device_alloc()

2023-08-17T07:21:40+00:00

Introduce a new helper, snd_device_alloc(), for allocating a struct device that is bound with the sound class. It's a replacement of snd_device_initialize(). Reviewed-by: Jaroslav Kysela Signed-off-by: Curtis Malainey Tested-by: Curtis Malainey Link: https://lore.kernel.org/r/20230816160252.23396-2-tiwai@suse.de Signed-off-by: Takashi Iwai

sound: make all 'class' structures const

2023-06-21T05:29:10+00:00

Now that the driver core allows for struct class to be in read-only memory, making all 'class' structures to be declared at build time placing them into read-only memory, instead of having to be dynamically allocated at load time. Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Ivan Orlov Cc: Greg Kroah-Hartman Cc: Geoff Levand Cc: Thierry Reding Cc: "Uwe Kleine-König" Cc: alsa-devel@alsa-project.org Suggested-by: Greg Kroah-Hartman Signed-off-by: Ivan Orlov Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20230620175633.641141-2-gregkh@linuxfoundation.org Signed-off-by: Takashi Iwai