diff options
| author | Jaroslav Kysela <perex@perex.cz> | 2009-04-15 10:16:24 +0200 |
|---|---|---|
| committer | Jaroslav Kysela <perex@perex.cz> | 2009-04-15 10:16:24 +0200 |
| commit | 2ec775e7053c82bc90858ede011b35aeb416995b (patch) | |
| tree | e0bbf9da43c2296eafc7d4c010669eb07c6132cb | |
| parent | 29dab4fd3176e25dfab6cd763beb02d87973c288 (diff) | |
[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>
| -rw-r--r-- | sound/pci/intel8x0.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c index 10f8609e9c6e..5dced5b79387 100644 --- a/sound/pci/intel8x0.c +++ b/sound/pci/intel8x0.c @@ -2676,12 +2676,13 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip) struct ichdev *ichdev; unsigned long port; unsigned long pos, pos1, t; - int civ, timeout = 1000; + int civ, timeout = 1000, attempt = 1; struct timespec start_time, stop_time; if (chip->ac97_bus->clock != 48000) return; /* specified in module option */ + __again: subs = chip->pcm[0]->streams[0].substream; if (! subs || subs->dma_buffer.bytes < INTEL8X0_TESTBUF_SIZE) { snd_printk(KERN_WARNING "no playback buffer allocated - aborting measure ac97 clock\n"); @@ -2749,6 +2750,11 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip) if (pos == 0) { snd_printk(KERN_ERR "intel8x0: measure - unreliable DMA position..\n"); + __retry: + if (attempt < 2) { + attempt++; + goto __again; + } return; } @@ -2759,14 +2765,15 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip) printk(KERN_INFO "%s: measured %lu usecs (%lu samples)\n", __func__, t, pos); if (t == 0) { snd_printk(KERN_ERR "intel8x0: ?? calculation error..\n"); - return; + goto __retry; } pos *= 1000; pos = (pos / t) * 1000 + ((pos % t) * 1000) / t; - if (pos < 40000 || pos >= 60000) + if (pos < 40000 || pos >= 60000) { /* abnormal value. hw problem? */ printk(KERN_INFO "intel8x0: measured clock %ld rejected\n", pos); - else if (pos > 40500 && pos < 41500) + goto __retry; + } else if (pos > 40500 && pos < 41500) /* first exception - 41000Hz reference clock */ chip->ac97_bus->clock = 41000; else if (pos > 43600 && pos < 44600) |