ALSA: intel8x0: implement ac97_clock whitelist
The AC97 clock detection is not accurate in some cases. This patch adds
an initial whitelist for audio devices gathered from RedHat's bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=441087
As a side effect, white-listing might speedup kernel booting (AC97 clock
measuring code is not activated).
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c
index 73ad589..c8f5148 100644
--- a/sound/pci/intel8x0.c
+++ b/sound/pci/intel8x0.c
@@ -83,7 +83,7 @@
module_param(id, charp, 0444);
MODULE_PARM_DESC(id, "ID string for Intel i8x0 soundcard.");
module_param(ac97_clock, int, 0444);
-MODULE_PARM_DESC(ac97_clock, "AC'97 codec clock (0 = auto-detect).");
+MODULE_PARM_DESC(ac97_clock, "AC'97 codec clock (0 = whitelist + auto-detect, 1 = force autodetect).");
module_param(ac97_quirk, charp, 0444);
MODULE_PARM_DESC(ac97_quirk, "AC'97 workaround for strange hardware.");
module_param(buggy_semaphore, bool, 0444);
@@ -2692,6 +2692,38 @@
snd_ac97_update_power(chip->ac97[0], AC97_PCM_FRONT_DAC_RATE, 0);
}
+struct intel8x0_clock_list {
+ unsigned short subvendor;
+ unsigned short subdevice;
+ unsigned int rate;
+};
+
+static struct intel8x0_clock_list intel8x0_clock_list[] __devinitdata = {
+ { 0x0e11, 0x008a, 41000 }, /* Analog Devices AD1885 */
+ { 0x1028, 0x00be, 44100 }, /* Analog Devices AD1885 */
+ { 0x1028, 0x0177, 48000 }, /* Analog Devices AD1980 */
+ { 0x1043, 0x80f3, 48000 }, /* Analog Devices AD1985 */
+ { 0x0000, 0x0000, 00000 } /* terminator */
+};
+
+static int __devinit intel8x0_in_clock_list(struct intel8x0 *chip)
+{
+ struct pci_dev *pci = chip->pci;
+ struct intel8x0_clock_list *wl;
+
+ for (wl = intel8x0_clock_list; wl->subvendor; wl++) {
+ if (wl->subvendor == pci->subsystem_vendor &&
+ wl->subdevice == pci->subsystem_device) {
+ printk(KERN_INFO "intel8x0: white list rate for %04x:%04x is %i\n",
+ pci->subsystem_vendor,
+ pci->subsystem_device, wl->rate);
+ chip->ac97_bus->clock = wl->rate;
+ return 1;
+ }
+ }
+ return 0;
+}
+
#ifdef CONFIG_PROC_FS
static void snd_intel8x0_proc_read(struct snd_info_entry * entry,
struct snd_info_buffer *buffer)
@@ -3087,8 +3119,14 @@
"%s with %s at irq %i", card->shortname,
snd_ac97_get_short_name(chip->ac97[0]), chip->irq);
- if (! ac97_clock)
- intel8x0_measure_ac97_clock(chip);
+ if (ac97_clock == 0 || ac97_clock == 1) {
+ if (ac97_clock == 0) {
+ if (intel8x0_in_clock_list(chip) == 0)
+ intel8x0_measure_ac97_clock(chip);
+ } else {
+ intel8x0_measure_ac97_clock(chip);
+ }
+ }
if ((err = snd_card_register(card)) < 0) {
snd_card_free(card);