ALSA: firewire-lib: fix insufficient PCM rule for period/buffer size

In a former commit, PCM constraint based on LCM of SYT_INTERVAL was
obsoleted with PCM rule. However, the new PCM rule brings -EINVAL in
some cases that max/min values of size of buffer/period is not
multiples of one of values of SYT_INTERVAL. For example, pulseaudio
always fail to configure PCM substream.

This commit changes strategy for the PCM rule. Although the buggy rules
had a single dependency (rate from period, period from rate, rate from
buffer, buffer from rate), a revised rule has double dependencies
(period from period/rate, buffer from buffer/rate). A step of value is
calculated with table of SYT_INTERVAL and list of available rates. This
prevents interval template which brings -EINVAL to a call of
snd_interval_refine().

Fixes: 5950229582bc('ALSA: firewire-lib: add PCM rules to obsolete PCM constraints based on LCM of SYT_INTERVAL')
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index fcd965f..9be76c8 100644 (file)
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -146,53 +146,22 @@ static int apply_constraint_to_size(struct snd_pcm_hw_params *params,
        struct snd_interval *s = hw_param_interval(params, rule->var);
        const struct snd_interval *r =
                hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
-       struct snd_interval t = {
-               .min = s->min, .max = s->max, .integer = 1,
-       };
+       struct snd_interval t = {0};
+       unsigned int step = 0;
        int i;
 
        for (i = 0; i < CIP_SFC_COUNT; ++i) {
-               unsigned int rate = amdtp_rate_table[i];
-               unsigned int step = amdtp_syt_intervals[i];
-
-               if (!snd_interval_test(r, rate))
-                       continue;
-
-               t.min = roundup(t.min, step);
-               t.max = rounddown(t.max, step);
+               if (snd_interval_test(r, amdtp_rate_table[i]))
+                       step = max(step, amdtp_syt_intervals[i]);
        }
 
-       if (snd_interval_checkempty(&t))
-               return -EINVAL;
+       t.min = roundup(s->min, step);
+       t.max = rounddown(s->max, step);
+       t.integer = 1;
 
        return snd_interval_refine(s, &t);
 }
 
-static int apply_constraint_to_rate(struct snd_pcm_hw_params *params,
-                                   struct snd_pcm_hw_rule *rule)
-{
-       struct snd_interval *r =
-                       hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
-       const struct snd_interval *s = hw_param_interval_c(params, rule->deps[0]);
-       struct snd_interval t = {
-               .min = UINT_MAX, .max = 0, .integer = 1,
-       };
-       int i;
-
-       for (i = 0; i < CIP_SFC_COUNT; ++i) {
-               unsigned int step = amdtp_syt_intervals[i];
-               unsigned int rate = amdtp_rate_table[i];
-
-               if (s->min % step || s->max % step)
-                       continue;
-
-               t.min = min(t.min, rate);
-               t.max = max(t.max, rate);
-       }
-
-       return snd_interval_refine(r, &t);
-}
-
 /**
  * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
  * @s:         the AMDTP stream, which must be initialized.
@@ -250,24 +219,16 @@ int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
         */
        err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
                                  apply_constraint_to_size, NULL,
+                                 SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
                                  SNDRV_PCM_HW_PARAM_RATE, -1);
        if (err < 0)
                goto end;
-       err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
-                                 apply_constraint_to_rate, NULL,
-                                 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
-       if (err < 0)
-               goto end;
        err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
                                  apply_constraint_to_size, NULL,
+                                 SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
                                  SNDRV_PCM_HW_PARAM_RATE, -1);
        if (err < 0)
                goto end;
-       err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
-                                 apply_constraint_to_rate, NULL,
-                                 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
-       if (err < 0)
-               goto end;
 end:
        return err;
 }