[PATCH 1/2] ALSA: usb-audio: Fix packet size calculation
Commit f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation") introduced a regression for devices which have playback endpoints with bInterval > 1. Fix this by taking ep->datainterval into account.
Note that frame and fps are actually mean packet and packets per second in the code introduces by the mentioned commit. This will be fixed in a follow-up patch.
Fixes: f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=208353 Signed-off-by: Alexander Tsoy alexander@tsoy.me --- sound/usb/endpoint.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index 9bea7d3f99f8..11f23778f0a5 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -1093,6 +1093,7 @@ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep, ep->freqn = get_usb_high_speed_rate(rate); ep->fps = 8000; } + ep->fps >>= ep->datainterval;
ep->sample_rem = rate % ep->fps; ep->framesize[0] = rate / ep->fps;
Replace several occurences of "frame" with a "packet" where appropriate.
Signed-off-by: Alexander Tsoy alexander@tsoy.me --- sound/usb/card.h | 6 +++--- sound/usb/endpoint.c | 19 +++++++++---------- 2 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/sound/usb/card.h b/sound/usb/card.h index d6219fba9699..de43267b9c8a 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -84,10 +84,10 @@ struct snd_usb_endpoint { dma_addr_t sync_dma; /* DMA address of syncbuf */
unsigned int pipe; /* the data i/o pipe */ - unsigned int framesize[2]; /* small/large frame sizes in samples */ - unsigned int sample_rem; /* remainder from division fs/fps */ + unsigned int packsize[2]; /* small/large packet sizes in samples */ + unsigned int sample_rem; /* remainder from division fs/pps */ unsigned int sample_accum; /* sample accumulator */ - unsigned int fps; /* frames per second */ + unsigned int pps; /* packets per second */ unsigned int freqn; /* nominal sampling rate in fs/fps in Q16.16 format */ unsigned int freqm; /* momentary sampling rate in fs/fps in Q16.16 format */ int freqshift; /* how much to shift the feedback value to get Q16.16 */ diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index 11f23778f0a5..88760268fb55 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -159,11 +159,11 @@ int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep) return ep->maxframesize;
ep->sample_accum += ep->sample_rem; - if (ep->sample_accum >= ep->fps) { - ep->sample_accum -= ep->fps; - ret = ep->framesize[1]; + if (ep->sample_accum >= ep->pps) { + ep->sample_accum -= ep->pps; + ret = ep->packsize[1]; } else { - ret = ep->framesize[0]; + ret = ep->packsize[0]; }
return ret; @@ -1088,16 +1088,15 @@ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL) { ep->freqn = get_usb_full_speed_rate(rate); - ep->fps = 1000; + ep->pps = 1000 >> ep->datainterval; } else { ep->freqn = get_usb_high_speed_rate(rate); - ep->fps = 8000; + ep->pps = 8000 >> ep->datainterval; } - ep->fps >>= ep->datainterval;
- ep->sample_rem = rate % ep->fps; - ep->framesize[0] = rate / ep->fps; - ep->framesize[1] = (rate + (ep->fps - 1)) / ep->fps; + ep->sample_rem = rate % ep->pps; + ep->packsize[0] = rate / ep->pps; + ep->packsize[1] = (rate + (ep->pps - 1)) / ep->pps;
/* calculate the frequency in 16.16 format */ ep->freqm = ep->freqn;
On Mon, 29 Jun 2020 04:59:34 +0200, Alexander Tsoy wrote:
Replace several occurences of "frame" with a "packet" where appropriate.
Signed-off-by: Alexander Tsoy alexander@tsoy.me
Applied, thanks.
Takashi
On Mon, 29 Jun 2020 04:59:33 +0200, Alexander Tsoy wrote:
Commit f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation") introduced a regression for devices which have playback endpoints with bInterval > 1. Fix this by taking ep->datainterval into account.
Note that frame and fps are actually mean packet and packets per second in the code introduces by the mentioned commit. This will be fixed in a follow-up patch.
Fixes: f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=208353 Signed-off-by: Alexander Tsoy alexander@tsoy.me
Applied now. Thanks.
Takashi
participants (2)
-
Alexander Tsoy -
Takashi Iwai