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[2/3] ALSA: docs: Add description about ack callback -EPIPE error handling

Message ID 20230323065237.5062-3-tiwai@suse.de (mailing list archive)
State New, archived
Headers show
Series ALSA: More PCM and documentation updates | expand

Commit Message

Takashi Iwai March 23, 2023, 6:52 a.m. UTC
Add a brief description about the newly added behavior of the PCM ack
callback with -EPIPE error.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
 Documentation/sound/kernel-api/writing-an-alsa-driver.rst | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series


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