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>

1 files changed, 9 insertions, 48 deletions

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index fcd965f1d69e..9be76c808fcc 100644
--- 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;
 }