[alsa-devel] [PATCH v7] ASoC: omap-mcbsp: Add PM QoS support for McBSP to prevent glitches
We can get audio errors if hitting deeper idle states on omaps:
[alsa.c:230] error: Fatal problem with alsa output, error -5. [audio.c:614] error: Error in writing audio (Input/output error?)!
This seems to happen with off mode idle enabled as power for the whole SoC may get cut off between filling the McBSP fifo using DMA. While active DMA blocks deeper idle states in hardware, McBSP activity does not seem to do so.
Basing the QoS latency calculation on the FIFO size, threshold, sample rate, and channels.
Based on the original patch by Tony Lindgren Link: https://patchwork.kernel.org/patch/9305867/
Cc: Tony Lindgren tony@atomide.com Cc: Peter Ujfalusi peter.ujfalusi@ti.com Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Matt Ranostay matt@ranostay.consulting --- Changes from v1: * add calculations for latency per number of FIFO locations
Changes from v2: * add missing mcbsp.h header change
Changes from v3: * base the latency calculations on threshold, buffer size, sample rate, and channels
Changes from v4: * using Peter Ujfalusi's suggestions for restoring a higher latency on audio stream completion, or if not applicable remove the QoS request
Changes from v5: * clean up latency checking logic * move logic to .prepare and .shutdown to avoid functions that can sleep
Changes from v6: * move QoS removal to asoc_mcbsp_remove from omap_mcbsp_cleanup * also remove header include that is unneeded
sound/soc/omap/mcbsp.h | 3 +++ sound/soc/omap/omap-mcbsp.c | 47 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 49 insertions(+), 1 deletion(-)
diff --git a/sound/soc/omap/mcbsp.h b/sound/soc/omap/mcbsp.h index 61e93b1c185d..46ae1269a698 100644 --- a/sound/soc/omap/mcbsp.h +++ b/sound/soc/omap/mcbsp.h @@ -323,8 +323,11 @@ struct omap_mcbsp {
unsigned int fmt; unsigned int in_freq; + unsigned int latency[2]; int clk_div; int wlen; + + struct pm_qos_request pm_qos_req; };
void omap_mcbsp_config(struct omap_mcbsp *mcbsp, diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c index d018e966e533..3b8c9724d496 100644 --- a/sound/soc/omap/omap-mcbsp.c +++ b/sound/soc/omap/omap-mcbsp.c @@ -157,6 +157,16 @@ static void omap_mcbsp_dai_shutdown(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { struct omap_mcbsp *mcbsp = snd_soc_dai_get_drvdata(cpu_dai); + int tx = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK); + int stream1 = tx ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE; + int stream2 = tx ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK; + + mcbsp->latency[stream1] = 0; + if (mcbsp->latency[stream2]) + pm_qos_update_request(&mcbsp->pm_qos_req, + mcbsp->latency[stream2]); + else + pm_qos_remove_request(&mcbsp->pm_qos_req);
if (!cpu_dai->active) { omap_mcbsp_free(mcbsp); @@ -164,6 +174,28 @@ static void omap_mcbsp_dai_shutdown(struct snd_pcm_substream *substream, } }
+static int omap_mcbsp_dai_prepare(struct snd_pcm_substream *substream, + struct snd_soc_dai *cpu_dai) +{ + struct omap_mcbsp *mcbsp = snd_soc_dai_get_drvdata(cpu_dai); + struct pm_qos_request *pm_qos_req = &mcbsp->pm_qos_req; + int tx = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK); + int stream1 = tx ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE; + int stream2 = tx ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK; + int latency = mcbsp->latency[stream2]; + + /* Prevent omap hardware from hitting off between FIFO fills */ + if (!latency || mcbsp->latency[stream1] < latency) + latency = mcbsp->latency[stream1]; + + if (pm_qos_request_active(pm_qos_req)) + pm_qos_update_request(pm_qos_req, latency); + else if (latency) + pm_qos_add_request(pm_qos_req, PM_QOS_CPU_DMA_LATENCY, latency); + + return 0; +} + static int omap_mcbsp_dai_trigger(struct snd_pcm_substream *substream, int cmd, struct snd_soc_dai *cpu_dai) { @@ -226,6 +258,7 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream, int wlen, channels, wpf; int pkt_size = 0; unsigned int format, div, framesize, master; + unsigned int buffer_size = mcbsp->pdata->buffer_size;
dma_data = snd_soc_dai_get_dma_data(cpu_dai, substream); channels = params_channels(params); @@ -240,7 +273,9 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream, default: return -EINVAL; } - if (mcbsp->pdata->buffer_size) { + if (buffer_size) { + int latency; + if (mcbsp->dma_op_mode == MCBSP_DMA_MODE_THRESHOLD) { int period_words, max_thrsh; int divider = 0; @@ -271,6 +306,12 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream, /* Use packet mode for non mono streams */ pkt_size = channels; } + + latency = ((((buffer_size - pkt_size) / channels) * 1000) + / (params->rate_num / params->rate_den)); + + mcbsp->latency[substream->stream] = latency; + omap_mcbsp_set_threshold(substream, pkt_size); }
@@ -554,6 +595,7 @@ static int omap_mcbsp_dai_set_dai_sysclk(struct snd_soc_dai *cpu_dai, static const struct snd_soc_dai_ops mcbsp_dai_ops = { .startup = omap_mcbsp_dai_startup, .shutdown = omap_mcbsp_dai_shutdown, + .prepare = omap_mcbsp_dai_prepare, .trigger = omap_mcbsp_dai_trigger, .delay = omap_mcbsp_dai_delay, .hw_params = omap_mcbsp_dai_hw_params, @@ -835,6 +877,9 @@ static int asoc_mcbsp_remove(struct platform_device *pdev) if (mcbsp->pdata->ops && mcbsp->pdata->ops->free) mcbsp->pdata->ops->free(mcbsp->id);
+ if (pm_qos_request_active(&mcbsp->pm_qos_req)) + pm_qos_remove_request(&mcbsp->pm_qos_req); + omap_mcbsp_cleanup(mcbsp);
clk_put(mcbsp->fclk);
* Matt Ranostay matt@ranostay.consulting [170112 19:55]:
We can get audio errors if hitting deeper idle states on omaps:
[alsa.c:230] error: Fatal problem with alsa output, error -5. [audio.c:614] error: Error in writing audio (Input/output error?)!
This seems to happen with off mode idle enabled as power for the whole SoC may get cut off between filling the McBSP fifo using DMA. While active DMA blocks deeper idle states in hardware, McBSP activity does not seem to do so.
Basing the QoS latency calculation on the FIFO size, threshold, sample rate, and channels.
Based on the original patch by Tony Lindgren Link: https://patchwork.kernel.org/patch/9305867/
Cc: Tony Lindgren tony@atomide.com Cc: Peter Ujfalusi peter.ujfalusi@ti.com Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Matt Ranostay matt@ranostay.consulting
Changes from v1:
- add calculations for latency per number of FIFO locations
Changes from v2:
- add missing mcbsp.h header change
Changes from v3:
- base the latency calculations on threshold, buffer size, sample rate, and channels
Changes from v4:
- using Peter Ujfalusi's suggestions for restoring a higher latency on audio stream completion, or if not applicable remove the QoS request
Changes from v5:
- clean up latency checking logic
- move logic to .prepare and .shutdown to avoid functions that can sleep
Changes from v6:
- move QoS removal to asoc_mcbsp_remove from omap_mcbsp_cleanup
- also remove header include that is unneeded
Hmm now I'm seeing these when starting or stopping playback:
WARNING: CPU: 0 PID: 373 at kernel/power/qos.c:534 omap_mcbsp_dai_shutdown+0x6c/0x70 [snd_soc_omap_mcbsp] pm_qos_remove_request() called for unknown object Modules linked in: snd_soc_omap_twl4030 snd_soc_twl4030 snd_soc_omap_mcbsp evdev mwifiex_sdio mwifiex leds_gpio snd_soc_omap cfg80211 bq27xxx_battery_i2c leds_pca963x bq27xxx_battery led_class bq24190_charger phy_twl4030_usb omap2430 mus b_hdrc usbcore snd_soc_core twl4030_wdt snd_pcm_dmaengine rtc_twl snd_pcm snd_timer snd soundcore twl4030_pwrbutton pwm_twl_le d twl4030_keypad pwm_twl matrix_keymap omap_ssi hsi ledtrig_timer usb_f_serial usb_f_rndis usb_f_mass_storage usb_f_ecm u_ethe r usb_f_acm libcomposite u_serial udc_core usb_common autofs4 [last unloaded: snd_soc_omap_mcbsp] [ 51.542541] CPU: 0 PID: 373 Comm: mpg123 Not tainted 4.10.0-rc2-next-20170109+ #751 [ 51.550231] Hardware name: Generic OMAP36xx (Flattened Device Tree) [ 51.556579] [<c0110198>] (unwind_backtrace) from [<c010c208>] (show_stack+0x10/0x14) [ 51.564361] [<c010c208>] (show_stack) from [<c04be0a0>] (dump_stack+0xac/0xe0) [ 51.571655] [<c04be0a0>] (dump_stack) from [<c0137428>] (__warn+0xd8/0x104) [ 51.578643] [<c0137428>] (__warn) from [<c0137488>] (warn_slowpath_fmt+0x34/0x44) [ 51.586212] [<c0137488>] (warn_slowpath_fmt) from [<bf3538f4>] (omap_mcbsp_dai_shutdown+0x6c/0x70 [snd_soc_omap_mcbsp]) [ 51.597351] [<bf3538f4>] (omap_mcbsp_dai_shutdown [snd_soc_omap_mcbsp]) from [<bf11037c>] (soc_pcm_close+0xa0/0x2b8 [snd_so c_core]) [ 51.609497] [<bf11037c>] (soc_pcm_close [snd_soc_core]) from [<bf0d0654>] (snd_pcm_release_substream.part.13+0x48/0xac [snd _pcm]) [ 51.621337] [<bf0d0654>] (snd_pcm_release_substream.part.13 [snd_pcm]) from [<bf0d0764>] (snd_pcm_release+0x94/0xb4 [snd_pc m]) [ 51.632843] [<bf0d0764>] (snd_pcm_release [snd_pcm]) from [<c02b91d8>] (__fput+0x94/0x1e4) [ 51.641174] [<c02b91d8>] (__fput) from [<c015b768>] (task_work_run+0xcc/0x104) [ 51.648437] [<c015b768>] (task_work_run) from [<c010bb38>] (do_work_pending+0xbc/0xc0) [ 51.656402] [<c010bb38>] (do_work_pending) from [<c01077c8>] (slow_work_pending+0xc/0x20)
Regards,
Tony
On Fri, Jan 13, 2017 at 7:20 AM, Tony Lindgren tony@atomide.com wrote:
- Matt Ranostay matt@ranostay.consulting [170112 19:55]:
We can get audio errors if hitting deeper idle states on omaps:
[alsa.c:230] error: Fatal problem with alsa output, error -5. [audio.c:614] error: Error in writing audio (Input/output error?)!
This seems to happen with off mode idle enabled as power for the whole SoC may get cut off between filling the McBSP fifo using DMA. While active DMA blocks deeper idle states in hardware, McBSP activity does not seem to do so.
Basing the QoS latency calculation on the FIFO size, threshold, sample rate, and channels.
Based on the original patch by Tony Lindgren Link: https://patchwork.kernel.org/patch/9305867/
Cc: Tony Lindgren tony@atomide.com Cc: Peter Ujfalusi peter.ujfalusi@ti.com Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Matt Ranostay matt@ranostay.consulting
Changes from v1:
- add calculations for latency per number of FIFO locations
Changes from v2:
- add missing mcbsp.h header change
Changes from v3:
- base the latency calculations on threshold, buffer size, sample rate, and channels
Changes from v4:
- using Peter Ujfalusi's suggestions for restoring a higher latency on audio stream completion, or if not applicable remove the QoS request
Changes from v5:
- clean up latency checking logic
- move logic to .prepare and .shutdown to avoid functions that can sleep
Changes from v6:
- move QoS removal to asoc_mcbsp_remove from omap_mcbsp_cleanup
- also remove header include that is unneeded
Hmm now I'm seeing these when starting or stopping playback:
Weird.. I'll test again tonight and get back to you
WARNING: CPU: 0 PID: 373 at kernel/power/qos.c:534 omap_mcbsp_dai_shutdown+0x6c/0x70 [snd_soc_omap_mcbsp] pm_qos_remove_request() called for unknown object Modules linked in: snd_soc_omap_twl4030 snd_soc_twl4030 snd_soc_omap_mcbsp evdev mwifiex_sdio mwifiex leds_gpio snd_soc_omap cfg80211 bq27xxx_battery_i2c leds_pca963x bq27xxx_battery led_class bq24190_charger phy_twl4030_usb omap2430 mus b_hdrc usbcore snd_soc_core twl4030_wdt snd_pcm_dmaengine rtc_twl snd_pcm snd_timer snd soundcore twl4030_pwrbutton pwm_twl_le d twl4030_keypad pwm_twl matrix_keymap omap_ssi hsi ledtrig_timer usb_f_serial usb_f_rndis usb_f_mass_storage usb_f_ecm u_ethe r usb_f_acm libcomposite u_serial udc_core usb_common autofs4 [last unloaded: snd_soc_omap_mcbsp] [ 51.542541] CPU: 0 PID: 373 Comm: mpg123 Not tainted 4.10.0-rc2-next-20170109+ #751 [ 51.550231] Hardware name: Generic OMAP36xx (Flattened Device Tree) [ 51.556579] [<c0110198>] (unwind_backtrace) from [<c010c208>] (show_stack+0x10/0x14) [ 51.564361] [<c010c208>] (show_stack) from [<c04be0a0>] (dump_stack+0xac/0xe0) [ 51.571655] [<c04be0a0>] (dump_stack) from [<c0137428>] (__warn+0xd8/0x104) [ 51.578643] [<c0137428>] (__warn) from [<c0137488>] (warn_slowpath_fmt+0x34/0x44) [ 51.586212] [<c0137488>] (warn_slowpath_fmt) from [<bf3538f4>] (omap_mcbsp_dai_shutdown+0x6c/0x70 [snd_soc_omap_mcbsp]) [ 51.597351] [<bf3538f4>] (omap_mcbsp_dai_shutdown [snd_soc_omap_mcbsp]) from [<bf11037c>] (soc_pcm_close+0xa0/0x2b8 [snd_so c_core]) [ 51.609497] [<bf11037c>] (soc_pcm_close [snd_soc_core]) from [<bf0d0654>] (snd_pcm_release_substream.part.13+0x48/0xac [snd _pcm]) [ 51.621337] [<bf0d0654>] (snd_pcm_release_substream.part.13 [snd_pcm]) from [<bf0d0764>] (snd_pcm_release+0x94/0xb4 [snd_pc m]) [ 51.632843] [<bf0d0764>] (snd_pcm_release [snd_pcm]) from [<c02b91d8>] (__fput+0x94/0x1e4) [ 51.641174] [<c02b91d8>] (__fput) from [<c015b768>] (task_work_run+0xcc/0x104) [ 51.648437] [<c015b768>] (task_work_run) from [<c010bb38>] (do_work_pending+0xbc/0xc0) [ 51.656402] [<c010bb38>] (do_work_pending) from [<c01077c8>] (slow_work_pending+0xc/0x20)
Regards,
Tony
On Fri, Jan 13, 2017 at 7:20 AM, Tony Lindgren tony@atomide.com wrote:
- Matt Ranostay matt@ranostay.consulting [170112 19:55]:
We can get audio errors if hitting deeper idle states on omaps:
[alsa.c:230] error: Fatal problem with alsa output, error -5. [audio.c:614] error: Error in writing audio (Input/output error?)!
This seems to happen with off mode idle enabled as power for the whole SoC may get cut off between filling the McBSP fifo using DMA. While active DMA blocks deeper idle states in hardware, McBSP activity does not seem to do so.
Basing the QoS latency calculation on the FIFO size, threshold, sample rate, and channels.
Based on the original patch by Tony Lindgren Link: https://patchwork.kernel.org/patch/9305867/
Cc: Tony Lindgren tony@atomide.com Cc: Peter Ujfalusi peter.ujfalusi@ti.com Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Matt Ranostay matt@ranostay.consulting
Changes from v1:
- add calculations for latency per number of FIFO locations
Changes from v2:
- add missing mcbsp.h header change
Changes from v3:
- base the latency calculations on threshold, buffer size, sample rate, and channels
Changes from v4:
- using Peter Ujfalusi's suggestions for restoring a higher latency on audio stream completion, or if not applicable remove the QoS request
Changes from v5:
- clean up latency checking logic
- move logic to .prepare and .shutdown to avoid functions that can sleep
Changes from v6:
- move QoS removal to asoc_mcbsp_remove from omap_mcbsp_cleanup
- also remove header include that is unneeded
Hmm now I'm seeing these when starting or stopping playback:
Ok I can't reproduce but I have an idea why it is happening. There is likely a race condition between pm_qos_remove_request() and omap_mcbsp_dai_shutdown()... Should we do a pm_qos_request_active check in omap_mcbsp_dai_shutdown? That seems to be hacking around the issue.
Thanks,
Matt
WARNING: CPU: 0 PID: 373 at kernel/power/qos.c:534 omap_mcbsp_dai_shutdown+0x6c/0x70 [snd_soc_omap_mcbsp] pm_qos_remove_request() called for unknown object Modules linked in: snd_soc_omap_twl4030 snd_soc_twl4030 snd_soc_omap_mcbsp evdev mwifiex_sdio mwifiex leds_gpio snd_soc_omap cfg80211 bq27xxx_battery_i2c leds_pca963x bq27xxx_battery led_class bq24190_charger phy_twl4030_usb omap2430 mus b_hdrc usbcore snd_soc_core twl4030_wdt snd_pcm_dmaengine rtc_twl snd_pcm snd_timer snd soundcore twl4030_pwrbutton pwm_twl_le d twl4030_keypad pwm_twl matrix_keymap omap_ssi hsi ledtrig_timer usb_f_serial usb_f_rndis usb_f_mass_storage usb_f_ecm u_ethe r usb_f_acm libcomposite u_serial udc_core usb_common autofs4 [last unloaded: snd_soc_omap_mcbsp] [ 51.542541] CPU: 0 PID: 373 Comm: mpg123 Not tainted 4.10.0-rc2-next-20170109+ #751 [ 51.550231] Hardware name: Generic OMAP36xx (Flattened Device Tree) [ 51.556579] [<c0110198>] (unwind_backtrace) from [<c010c208>] (show_stack+0x10/0x14) [ 51.564361] [<c010c208>] (show_stack) from [<c04be0a0>] (dump_stack+0xac/0xe0) [ 51.571655] [<c04be0a0>] (dump_stack) from [<c0137428>] (__warn+0xd8/0x104) [ 51.578643] [<c0137428>] (__warn) from [<c0137488>] (warn_slowpath_fmt+0x34/0x44) [ 51.586212] [<c0137488>] (warn_slowpath_fmt) from [<bf3538f4>] (omap_mcbsp_dai_shutdown+0x6c/0x70 [snd_soc_omap_mcbsp]) [ 51.597351] [<bf3538f4>] (omap_mcbsp_dai_shutdown [snd_soc_omap_mcbsp]) from [<bf11037c>] (soc_pcm_close+0xa0/0x2b8 [snd_so c_core]) [ 51.609497] [<bf11037c>] (soc_pcm_close [snd_soc_core]) from [<bf0d0654>] (snd_pcm_release_substream.part.13+0x48/0xac [snd _pcm]) [ 51.621337] [<bf0d0654>] (snd_pcm_release_substream.part.13 [snd_pcm]) from [<bf0d0764>] (snd_pcm_release+0x94/0xb4 [snd_pc m]) [ 51.632843] [<bf0d0764>] (snd_pcm_release [snd_pcm]) from [<c02b91d8>] (__fput+0x94/0x1e4) [ 51.641174] [<c02b91d8>] (__fput) from [<c015b768>] (task_work_run+0xcc/0x104) [ 51.648437] [<c015b768>] (task_work_run) from [<c010bb38>] (do_work_pending+0xbc/0xc0) [ 51.656402] [<c010bb38>] (do_work_pending) from [<c01077c8>] (slow_work_pending+0xc/0x20)
Regards,
Tony
* Matt Ranostay matt@ranostay.consulting [170113 21:16]:
On Fri, Jan 13, 2017 at 7:20 AM, Tony Lindgren tony@atomide.com wrote:
- Matt Ranostay matt@ranostay.consulting [170112 19:55]:
We can get audio errors if hitting deeper idle states on omaps:
[alsa.c:230] error: Fatal problem with alsa output, error -5. [audio.c:614] error: Error in writing audio (Input/output error?)!
This seems to happen with off mode idle enabled as power for the whole SoC may get cut off between filling the McBSP fifo using DMA. While active DMA blocks deeper idle states in hardware, McBSP activity does not seem to do so.
Basing the QoS latency calculation on the FIFO size, threshold, sample rate, and channels.
Based on the original patch by Tony Lindgren Link: https://patchwork.kernel.org/patch/9305867/
Cc: Tony Lindgren tony@atomide.com Cc: Peter Ujfalusi peter.ujfalusi@ti.com Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Matt Ranostay matt@ranostay.consulting
Changes from v1:
- add calculations for latency per number of FIFO locations
Changes from v2:
- add missing mcbsp.h header change
Changes from v3:
- base the latency calculations on threshold, buffer size, sample rate, and channels
Changes from v4:
- using Peter Ujfalusi's suggestions for restoring a higher latency on audio stream completion, or if not applicable remove the QoS request
Changes from v5:
- clean up latency checking logic
- move logic to .prepare and .shutdown to avoid functions that can sleep
Changes from v6:
- move QoS removal to asoc_mcbsp_remove from omap_mcbsp_cleanup
- also remove header include that is unneeded
Hmm now I'm seeing these when starting or stopping playback:
Ok I can't reproduce but I have an idea why it is happening. There is likely a race condition between pm_qos_remove_request() and omap_mcbsp_dai_shutdown()... Should we do a pm_qos_request_active check in omap_mcbsp_dai_shutdown? That seems to be hacking around the issue.
OK. Again this is with next using omap2plus_defconfig and:
CONFIG_DEBUG_LOCKDEP=y CONFIG_DEBUG_ATOMIC_SLEEP=y
Regards,
Tony
On Mon, Jan 16, 2017 at 9:17 AM, Tony Lindgren tony@atomide.com wrote:
- Matt Ranostay matt@ranostay.consulting [170113 21:16]:
On Fri, Jan 13, 2017 at 7:20 AM, Tony Lindgren tony@atomide.com wrote:
- Matt Ranostay matt@ranostay.consulting [170112 19:55]:
We can get audio errors if hitting deeper idle states on omaps:
[alsa.c:230] error: Fatal problem with alsa output, error -5. [audio.c:614] error: Error in writing audio (Input/output error?)!
This seems to happen with off mode idle enabled as power for the whole SoC may get cut off between filling the McBSP fifo using DMA. While active DMA blocks deeper idle states in hardware, McBSP activity does not seem to do so.
Basing the QoS latency calculation on the FIFO size, threshold, sample rate, and channels.
Based on the original patch by Tony Lindgren Link: https://patchwork.kernel.org/patch/9305867/
Cc: Tony Lindgren tony@atomide.com Cc: Peter Ujfalusi peter.ujfalusi@ti.com Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Matt Ranostay matt@ranostay.consulting
Changes from v1:
- add calculations for latency per number of FIFO locations
Changes from v2:
- add missing mcbsp.h header change
Changes from v3:
- base the latency calculations on threshold, buffer size, sample rate, and channels
Changes from v4:
- using Peter Ujfalusi's suggestions for restoring a higher latency on audio stream completion, or if not applicable remove the QoS request
Changes from v5:
- clean up latency checking logic
- move logic to .prepare and .shutdown to avoid functions that can sleep
Changes from v6:
- move QoS removal to asoc_mcbsp_remove from omap_mcbsp_cleanup
- also remove header include that is unneeded
Hmm now I'm seeing these when starting or stopping playback:
Ok I can't reproduce but I have an idea why it is happening. There is likely a race condition between pm_qos_remove_request() and omap_mcbsp_dai_shutdown()... Should we do a pm_qos_request_active check in omap_mcbsp_dai_shutdown? That seems to be hacking around the issue.
OK. Again this is with next using omap2plus_defconfig and:
CONFIG_DEBUG_LOCKDEP=y CONFIG_DEBUG_ATOMIC_SLEEP=y
Yep I was testing with that enabled. Not sure why I'm not getting it all... maybe different side effects like sample rate of the audio being played?
Peter, is there chance that there is race condition is possible between pm_qos_remove_request and omap_mcbsp_dai_shutdown?
Regards,
Tony
On 01/16/2017 09:30 PM, Matt Ranostay wrote:
Yep I was testing with that enabled. Not sure why I'm not getting it all... maybe different side effects like sample rate of the audio being played?
Peter, is there chance that there is race condition is possible between pm_qos_remove_request and omap_mcbsp_dai_shutdown?
Not with my knowledge. However one thing might happen which is not handled: application opens up the audio card, does some hw_param setup, then it decides to close the card. In this case the pm_qos is not placed, but in dai_shutdown we try to remove it -> WARN().
I think we need to check either if the pm_qos is active and only then bother with the removal/updated or we can check if the mcbsp->latency[stream1] is not 0, which should be the same as checking for the pm_qos active.
On Tue, Jan 17, 2017 at 4:34 AM, Peter Ujfalusi peter.ujfalusi@ti.com wrote:
On 01/16/2017 09:30 PM, Matt Ranostay wrote:
Yep I was testing with that enabled. Not sure why I'm not getting it all... maybe different side effects like sample rate of the audio being played?
Peter, is there chance that there is race condition is possible between pm_qos_remove_request and omap_mcbsp_dai_shutdown?
Not with my knowledge. However one thing might happen which is not handled: application opens up the audio card, does some hw_param setup, then it decides to close the card. In this case the pm_qos is not placed, but in dai_shutdown we try to remove it -> WARN().
I think we need to check either if the pm_qos is active and only then bother with the removal/updated or we can check if the mcbsp->latency[stream1] is not 0, which should be the same as checking for the pm_qos active
Ok makes sense. Weird I'm not seeing it but I wanted to be sure adding checks wasn't just hiding a issue. Will submit v8... and hopefully that is the final one! *fingers crossed*
-- Péter
participants (3)
-
Matt Ranostay -
Peter Ujfalusi -
Tony Lindgren