[ALSA] intel8x0: add one retry to the ac97_clock measurement routine
It seems that on some hardware platforms, the first measurement is wrong. This patch adds second measurement to this case. Signed-off-by: Jaroslav Kysela <perex@perex.cz>
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@ -2676,12 +2676,13 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip)
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struct ichdev *ichdev;
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unsigned long port;
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unsigned long pos, pos1, t;
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int civ, timeout = 1000;
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int civ, timeout = 1000, attempt = 1;
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struct timespec start_time, stop_time;
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if (chip->ac97_bus->clock != 48000)
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return; /* specified in module option */
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__again:
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subs = chip->pcm[0]->streams[0].substream;
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if (! subs || subs->dma_buffer.bytes < INTEL8X0_TESTBUF_SIZE) {
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snd_printk(KERN_WARNING "no playback buffer allocated - aborting measure ac97 clock\n");
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@ -2749,6 +2750,11 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip)
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if (pos == 0) {
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snd_printk(KERN_ERR "intel8x0: measure - unreliable DMA position..\n");
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__retry:
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if (attempt < 2) {
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attempt++;
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goto __again;
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}
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return;
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}
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@ -2759,14 +2765,15 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip)
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printk(KERN_INFO "%s: measured %lu usecs (%lu samples)\n", __func__, t, pos);
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if (t == 0) {
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snd_printk(KERN_ERR "intel8x0: ?? calculation error..\n");
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return;
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goto __retry;
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}
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pos *= 1000;
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pos = (pos / t) * 1000 + ((pos % t) * 1000) / t;
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if (pos < 40000 || pos >= 60000)
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if (pos < 40000 || pos >= 60000) {
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/* abnormal value. hw problem? */
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printk(KERN_INFO "intel8x0: measured clock %ld rejected\n", pos);
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else if (pos > 40500 && pos < 41500)
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goto __retry;
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} else if (pos > 40500 && pos < 41500)
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/* first exception - 41000Hz reference clock */
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chip->ac97_bus->clock = 41000;
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else if (pos > 43600 && pos < 44600)
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