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Re-work ac97 initialization to match cold reset described in AC97r.23

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and be prepared to wait much longer for codec to become ready.

Credit to Hugo D. Valentim <hvalentim@gmx.net> for reporting the
problem, providing useful pointers, and repeated diff testing.
This commit is contained in:
Orion Hodson 2003-03-26 06:11:36 +00:00
parent 8f832fd0ba
commit abe88fc972
1 changed files with 19 additions and 12 deletions
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31
sys/dev/sound/pci/via82c686.c
View File

@ -462,7 +462,7 @@ via_attach(device_t dev)
{
struct via_info *via = 0;
char status[SND_STATUSLEN];
u_int32_t data;
u_int32_t data, cnt;
if ((via = malloc(sizeof *via, M_DEVBUF, M_NOWAIT | M_ZERO)) == NULL) {
device_printf(dev, "cannot allocate softc\n");
@ -476,18 +476,25 @@ via_attach(device_t dev)
data = pci_read_config(dev, PCIR_COMMAND, 2);
/* Wake up and reset AC97 if necessary */
if (!(pci_read_config(dev, VIA_AC97STATUS, 1) & VIA_AC97STATUS_RDY)) {
pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_EN | VIA_ACLINK_NRST | VIA_ACLINK_SYNC, 1);
DELAY(1000);
pci_write_config(dev, VIA_ACLINKCTRL, 0, 1);
DELAY(1000);
pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_DESIRED, 1);
DELAY(1000);
}
data = pci_read_config(dev, VIA_AC97STATUS, 1);
if ((data & VIA_AC97STATUS_RDY) == 0) {
/* Cold reset per ac97r2.3 spec (page 95) */
pci_write_config(dev, VIA_ACLINKCTRL, 0, 1); /* Assert low */
DELAY(100); /* Wait T_rst_low */
pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_NRST, 1); /* Assert high */
DELAY(1); /* Wait T_rst2clk */
pci_write_config(dev, VIA_ACLINKCTRL, 0, 1); /* Assert low */
if (pci_read_config(dev, VIA_ACLINKCTRL, 1) != VIA_ACLINK_DESIRED) {
pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_DESIRED, 1);
DELAY(1000);
/* Power everything up */
pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_DESIRED, 1);
/* Wait for codec to become ready (largest reported delay here 310ms) */
for (cnt = 0; cnt < 2000; cnt++) {
data = pci_read_config(dev, VIA_AC97STATUS, 1);
if (data & VIA_AC97STATUS_RDY)
break;
DELAY(5000);
}
}
via->regid = PCIR_MAPS;