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authorTakashi Iwai <tiwai@suse.de>2023-03-23 07:52:36 +0100
committerTakashi Iwai <tiwai@suse.de>2023-03-24 14:52:58 +0100
commitf84af109f6ca6eba5fd3031cb5b85907a607b2b3 (patch)
treea1d4b6a94abbbda511196ba68cfdafe0a2e01f58 /Documentation/sound
parentALSA: pcm: Improved XRUN handling for indirect PCM helpers (diff)
downloadlinux-f84af109f6ca6eba5fd3031cb5b85907a607b2b3.tar.xz
linux-f84af109f6ca6eba5fd3031cb5b85907a607b2b3.zip
ALSA: docs: Add description about ack callback -EPIPE error handling
Add a brief description about the newly added behavior of the PCM ack callback with -EPIPE error. Link: https://lore.kernel.org/r/20230323065237.5062-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'Documentation/sound')
-rw-r--r--Documentation/sound/kernel-api/writing-an-alsa-driver.rst4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
index 5c9523b7d55c..6b8f3495407f 100644
--- a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
+++ b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
@@ -2137,6 +2137,10 @@ This callback is also not mandatory. This callback is called when the
emu10k1-fx and cs46xx need to track the current ``appl_ptr`` for the
internal buffer, and this callback is useful only for such a purpose.
+The callback function may return 0 or a negative error. When the
+return value is ``-EPIPE``, PCM core treats as a buffer XRUN happens,
+and changes the state to ``SNDRV_PCM_STATE_XRUN`` automatically.
+
This callback is atomic as default.
page callback