From a7d9c0990d5503775784fef7ff44d74d7e3294fd Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Fri, 3 Apr 2009 09:48:26 +0200 Subject: [PATCH] sound: usb-audio: allow period sizes less than 1 ms To enable periods shorter than 1 ms, we have to make sure that short periods are only available for alternate settings that have a small enough data packet interval. Furthermore, the code that aligns URBs to USB frames is now superfluous. Signed-off-by: Clemens Ladisch Signed-off-by: Takashi Iwai --- sound/usb/usbaudio.c | 106 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 86 insertions(+), 20 deletions(-) diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c index 3f974a64c55..823296d7d57 100644 --- a/sound/usb/usbaudio.c +++ b/sound/usb/usbaudio.c @@ -171,7 +171,6 @@ struct snd_usb_substream { unsigned int curframesize; /* current packet size in frames (for capture) */ unsigned int fill_max: 1; /* fill max packet size always */ unsigned int fmt_type; /* USB audio format type (1-3) */ - unsigned int packs_per_ms; /* packets per millisecond (for playback) */ unsigned int running: 1; /* running status */ @@ -608,9 +607,7 @@ static int prepare_playback_urb(struct snd_usb_substream *subs, break; } } - /* finish at the frame boundary at/after the period boundary */ - if (period_elapsed && - (i & (subs->packs_per_ms - 1)) == subs->packs_per_ms - 1) + if (period_elapsed) /* finish at the period boundary */ break; } if (subs->hwptr_done + offs > runtime->buffer_size) { @@ -1068,7 +1065,6 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri packs_per_ms = 8 >> subs->datainterval; else packs_per_ms = 1; - subs->packs_per_ms = packs_per_ms; if (is_playback) { urb_packs = max(nrpacks, 1); @@ -1088,18 +1084,17 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri minsize -= minsize >> 3; minsize = max(minsize, 1u); total_packs = (period_bytes + minsize - 1) / minsize; - /* round up to multiple of packs_per_ms */ - total_packs = (total_packs + packs_per_ms - 1) - & ~(packs_per_ms - 1); /* we need at least two URBs for queueing */ - if (total_packs < 2 * packs_per_ms) { - total_packs = 2 * packs_per_ms; + if (total_packs < 2) { + total_packs = 2; } else { /* and we don't want too long a queue either */ maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2); total_packs = min(total_packs, maxpacks); } } else { + while (urb_packs > 1 && urb_packs * maxsize >= period_bytes) + urb_packs >>= 1; total_packs = MAX_URBS * urb_packs; } subs->nurbs = (total_packs + urb_packs - 1) / urb_packs; @@ -1564,11 +1559,15 @@ static struct snd_pcm_hardware snd_usb_hardware = #define hwc_debug(fmt, args...) /**/ #endif -static int hw_check_valid_format(struct snd_pcm_hw_params *params, struct audioformat *fp) +static int hw_check_valid_format(struct snd_usb_substream *subs, + struct snd_pcm_hw_params *params, + struct audioformat *fp) { struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE); struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS); struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT); + struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME); + unsigned int ptime; /* check the format */ if (!snd_mask_test(fmts, fp->format)) { @@ -1589,6 +1588,14 @@ static int hw_check_valid_format(struct snd_pcm_hw_params *params, struct audiof hwc_debug(" > check: rate_max %d < min %d\n", fp->rate_max, it->min); return 0; } + /* check whether the period time is >= the data packet interval */ + if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH) { + ptime = 125 * (1 << fp->datainterval); + if (ptime > pt->max || (ptime == pt->max && pt->openmax)) { + hwc_debug(" > check: ptime %u > max %u\n", ptime, pt->max); + return 0; + } + } return 1; } @@ -1607,7 +1614,7 @@ static int hw_rule_rate(struct snd_pcm_hw_params *params, list_for_each(p, &subs->fmt_list) { struct audioformat *fp; fp = list_entry(p, struct audioformat, list); - if (!hw_check_valid_format(params, fp)) + if (!hw_check_valid_format(subs, params, fp)) continue; if (changed++) { if (rmin > fp->rate_min) @@ -1661,7 +1668,7 @@ static int hw_rule_channels(struct snd_pcm_hw_params *params, list_for_each(p, &subs->fmt_list) { struct audioformat *fp; fp = list_entry(p, struct audioformat, list); - if (!hw_check_valid_format(params, fp)) + if (!hw_check_valid_format(subs, params, fp)) continue; if (changed++) { if (rmin > fp->channels) @@ -1714,7 +1721,7 @@ static int hw_rule_format(struct snd_pcm_hw_params *params, list_for_each(p, &subs->fmt_list) { struct audioformat *fp; fp = list_entry(p, struct audioformat, list); - if (!hw_check_valid_format(params, fp)) + if (!hw_check_valid_format(subs, params, fp)) continue; fbits |= (1ULL << fp->format); } @@ -1732,6 +1739,44 @@ static int hw_rule_format(struct snd_pcm_hw_params *params, return changed; } +static int hw_rule_period_time(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + struct snd_usb_substream *subs = rule->private; + struct audioformat *fp; + struct snd_interval *it; + unsigned char min_datainterval; + unsigned int pmin; + int changed; + + it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME); + hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max); + min_datainterval = 0xff; + list_for_each_entry(fp, &subs->fmt_list, list) { + if (!hw_check_valid_format(subs, params, fp)) + continue; + min_datainterval = min(min_datainterval, fp->datainterval); + } + if (min_datainterval == 0xff) { + hwc_debug(" --> get emtpy\n"); + it->empty = 1; + return -EINVAL; + } + pmin = 125 * (1 << min_datainterval); + changed = 0; + if (it->min < pmin) { + it->min = pmin; + it->openmin = 0; + changed = 1; + } + if (snd_interval_checkempty(it)) { + it->empty = 1; + return -EINVAL; + } + hwc_debug(" --> (%u,%u) (changed = %d)\n", it->min, it->max, changed); + return changed; +} + /* * If the device supports unusual bit rates, does the request meet these? */ @@ -1777,6 +1822,8 @@ static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime, static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs) { struct list_head *p; + unsigned int pt, ptmin; + int param_period_time_if_needed; int err; runtime->hw.formats = subs->formats; @@ -1786,6 +1833,7 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre runtime->hw.channels_min = 256; runtime->hw.channels_max = 0; runtime->hw.rates = 0; + ptmin = UINT_MAX; /* check min/max rates and channels */ list_for_each(p, &subs->fmt_list) { struct audioformat *fp; @@ -1804,34 +1852,52 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre runtime->hw.period_bytes_min = runtime->hw.period_bytes_max = fp->frame_size; } + pt = 125 * (1 << fp->datainterval); + ptmin = min(ptmin, pt); } - /* set the period time minimum 1ms */ - /* FIXME: high-speed mode allows 125us minimum period, but many parts - * in the current code assume the 1ms period. - */ + param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME; + if (snd_usb_get_speed(subs->dev) != USB_SPEED_HIGH) + /* full speed devices have fixed data packet interval */ + ptmin = 1000; + if (ptmin == 1000) + /* if period time doesn't go below 1 ms, no rules needed */ + param_period_time_if_needed = -1; snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME, - 1000, - /*(nrpacks * MAX_URBS) * 1000*/ UINT_MAX); + ptmin, UINT_MAX); if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, hw_rule_rate, subs, SNDRV_PCM_HW_PARAM_FORMAT, SNDRV_PCM_HW_PARAM_CHANNELS, + param_period_time_if_needed, -1)) < 0) return err; if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, hw_rule_channels, subs, SNDRV_PCM_HW_PARAM_FORMAT, SNDRV_PCM_HW_PARAM_RATE, + param_period_time_if_needed, -1)) < 0) return err; if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT, hw_rule_format, subs, SNDRV_PCM_HW_PARAM_RATE, SNDRV_PCM_HW_PARAM_CHANNELS, + param_period_time_if_needed, -1)) < 0) return err; + if (param_period_time_if_needed >= 0) { + err = snd_pcm_hw_rule_add(runtime, 0, + SNDRV_PCM_HW_PARAM_PERIOD_TIME, + hw_rule_period_time, subs, + SNDRV_PCM_HW_PARAM_FORMAT, + SNDRV_PCM_HW_PARAM_CHANNELS, + SNDRV_PCM_HW_PARAM_RATE, + -1); + if (err < 0) + return err; + } if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0) return err; return 0; -- 2.41.1