Hi all,
I would like to ask you , ALSA gurus for some help.
What is exact meaning if "pointer" operations.
I know, that it should return offset in DMA buffer. What I'm not sure
about is unit - should the offset be in frames or in bytes. And should
it be offset against begin of DMA buffer (runtime->dma_addr) or
against actual period begin?
I'm writing ALSA driver for UDA1341 on Compaq iPAQ (H3600). It produce
some sound yet, but it's far from beeing usable. Actually I'm forking on
DMA part, and I got these messages from ALSA core (included in my debug
listing). If you could give me some hint, what this should be about, I
will be pleased :) (listing is a bit longer :(
command:
aplay -traw -c2 -r8000 -fS16_LE /usr/local/tmp/test3.raw
dmesg:
...
playback trigger
pcm_trigger id: 0 cmd: 1
rate: 8000
channels: 2
period_size 1000
periods: 4
buffer_size: 4000
dma_addr c1164000
dma_bytes: 16000
dma_area: 51 00 13 01 25 00 e2 00 a9 ff 65 00
process_dma
sending period 4 (buffer_size: 4000)
dma_bytes: 16000
offset: 0
dma_size: 4000
data: 51 00 13 01 25 00 e2 00 a9 ff 65 00
OK
sending period 3 (buffer_size: 4000)
dma_bytes: 16000
offset: 4000
dma_size: 4000
data: 44 ff 01 00 21 ff de ff 08 ff cb ff
OK
sending period 2 (buffer_size: 4000)
dma_bytes: 16000
offset: 8000
dma_size: 4000
data: 69 31 83 32 88 33 a9 34 81 29 8d 2a
pcm trigger done
playback pointer
get_dma_pos 1320 -> 1320 -> 1320 -> 330
min_align: 1
hw_ptr_base: 00000000
hw_ptr_interrupt: 00000000
period_size: 1000
updated pos: 330
dma_call_back
-> period done (still pending 1) <-
playback pointer
get_dma_pos 4256 -> 256 -> 256 -> 64
min_align: 1
hw_ptr_base: 00000000
hw_ptr_interrupt: 00000000
period_size: 1000
updated pos: 64
ALSA ../alsa-kernel/core/pcm_lib.c:120: U1nexpected hw_pointer value
(stream = 0, delta: -936, max jitter = 2000): wrong interrupt acknowledge?
process_dma
sending period 2 (buffer_size: 4000)
dma_bytes: 16000
offset: 8000
dma_size: 4000
data: 69 31 83 32 88 33 a9 34 81 29 8d 2a
OK
sending period 1 (buffer_size: 4000)
dma_bytes: 16000
offset: 12000
dma_size: 4000
data: 06 00 c3 00 4a fb fa fb 01 fa b5 fa
dma_callback done
dma_call_back
-> period done (still pending 1) <-
playback pointer
get_dma_pos 8296 -> 296 -> 296 -> 74
min_align: 1
hw_ptr_base: 00000000
hw_ptr_interrupt: 00000000
period_size: 1000
updated pos: 74
ALSA ../alsa-kernel/core/pcm_lib.c:120: U1nexpected hw_pointer value
(stream = 0, delta: -926, max jitter = 2000): wrong interrupt acknowledge?
Thanks
--
Tomas Kasparek (sioux, xkaspa06)
Tomas.Kasparek@[seznam.cz,volny.cz]
[EMAIL PROTECTED]
student UIVT FEI VUT Brno
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