| Message ID | 1531996140-19880-1-git-send-email-twischer@de.adit-jv.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi all, Any comments to the patch in [1]? Should I change anything? [1] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-July/138319.html Best regards *Timo Wischer* *A*dvanced *D*river *I*nformation *T*echnology GmbH Engineering Software Base (ADITG/ESB) Robert-Bosch-Str. 200 31139 Hildesheim Germany Tel. +49 5121 49 6938 Fax +49 5121 49 6999 twischer@de.adit-jv.com ADIT is a joint venture company of Robert Bosch GmbH/Robert Bosch Car Multimedia GmbH and DENSO Corporation Sitz: Hildesheim, Registergericht: Amtsgericht Hildesheim HRB 3438 Geschäftsführung: Wilhelm Grabow, Ken Yaguchi On 07/19/2018 12:29 PM, twischer@de.adit-jv.com wrote: > From: Andreas Pape <apape@de.adit-jv.com> > > Setting pointer and afterwards check for wrap around leads > to the possibility of returning the inconsistent pointer position. > This patch increments buffer pointer atomically to avoid this issue. > > Signed-off-by: Andreas Pape <apape@de.adit-jv.com> > > Since commit: b7ae6f3 dmaengine implementation has been moved > from ASoC to ALSA core. So change goes to sound/soc/soc-dmaengine-pcm.c, > apply to sound/core/pcm_dmaengine.c now > > cherry picked from ADIT v3.14 e2f803f("ALSA: SOC: DMA: increment buffer pointer atomically") > Signed-off-by: Veeraiyan Chidambaram <veeraiyan.chidambaram@in.bosch.com> > (cherry picked from ADIT v4.1 commit 9e7eff10a38157db75f12e032fc378d3104a2812) > Signed-off-by: Takashi Sakamoto <takashi.sakamoto@miraclelinux.com> > (cherry picked from ADIT v4.9 commit 66c00aa1e7cd3b077fc2e5a45a4594b86246cf78) > Signed-off-by: Jiada Wang <jiada_wang@mentor.com> > > Signed-off-by: Timo Wischer <twischer@de.adit-jv.com> > --- > > v1 can be found in > http://mailman.alsa-project.org/pipermail/alsa-devel/2016-November/115277.html > > diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c > index 8eb58c7..0a7ed85 100644 > --- a/sound/core/pcm_dmaengine.c > +++ b/sound/core/pcm_dmaengine.c > @@ -139,12 +139,14 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); > > static void dmaengine_pcm_dma_complete(void *arg) > { > + unsigned int new_pos; > struct snd_pcm_substream *substream = arg; > struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); > > - prtd->pos += snd_pcm_lib_period_bytes(substream); > - if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream)) > - prtd->pos = 0; > + new_pos = READ_ONCE(prtd->pos) + snd_pcm_lib_period_bytes(substream); > + if (new_pos >= snd_pcm_lib_buffer_bytes(substream)) > + new_pos = 0; > + WRITE_ONCE(prtd->pos, new_pos); > > snd_pcm_period_elapsed(substream); > } > @@ -235,7 +237,7 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); > snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) > { > struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); > - return bytes_to_frames(substream->runtime, prtd->pos); > + return bytes_to_frames(substream->runtime, READ_ONCE(prtd->pos)); > } > EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); >
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c index 8eb58c7..0a7ed85 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -139,12 +139,14 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); static void dmaengine_pcm_dma_complete(void *arg) { + unsigned int new_pos; struct snd_pcm_substream *substream = arg; struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); - prtd->pos += snd_pcm_lib_period_bytes(substream); - if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream)) - prtd->pos = 0; + new_pos = READ_ONCE(prtd->pos) + snd_pcm_lib_period_bytes(substream); + if (new_pos >= snd_pcm_lib_buffer_bytes(substream)) + new_pos = 0; + WRITE_ONCE(prtd->pos, new_pos); snd_pcm_period_elapsed(substream); } @@ -235,7 +237,7 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) { struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); - return bytes_to_frames(substream->runtime, prtd->pos); + return bytes_to_frames(substream->runtime, READ_ONCE(prtd->pos)); } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);