@@ -21,7 +21,7 @@ config SND_HDA_EXT_CORE
select SND_HDA_CORE
config SND_HDA_PREALLOC_SIZE
- int "Pre-allocated buffer size for HD-audio driver" if !SND_DMA_SGBUF
+ int "Pre-allocated buffer size for HD-audio driver"
range 0 32768
default 0 if SND_DMA_SGBUF
default 64 if !SND_DMA_SGBUF
@@ -30,7 +30,8 @@ config SND_HDA_PREALLOC_SIZE
HD-audio driver. A larger buffer (e.g. 2048) is preferred
for systems using PulseAudio. The default 64 is chosen just
for compatibility reasons.
- On x86 systems, the default is zero as we need no preallocation.
+ On x86 systems, the default is zero as S/G allocation works
+ and no preallocation is needed in most cases.
Note that the pre-allocation size can be changed dynamically
via a proc file (/proc/asound/card*/pcm*/sub*/prealloc), too.
Since there are a few corner cases where the S/G buffer allocation isn't performed (e.g. depending on IOMMU implementations), it'd be better to allow the default buffer preallocation size for x86, too. The default for x86 is still kept to 0, as it should work in most cases. Signed-off-by: Takashi Iwai <tiwai@suse.de> --- sound/hda/Kconfig | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)