sound: oxygen: fix for PI7C9X110 compatibility

If the card is used with a Pericom PI7C9X110 PCI-E/PCI bridge,
reconfigure the latter's PCI buffering to fix an unknown problem.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/oxygen/oxygen_lib.c b/sound/pci/oxygen/oxygen_lib.c
index c9f2714..9c5e645 100644 (file)
--- a/sound/pci/oxygen/oxygen_lib.c
+++ b/sound/pci/oxygen/oxygen_lib.c
@@ -307,6 +307,28 @@ static void oxygen_restore_eeprom(struct oxygen *chip,
        }
 }
 
+static void pci_bridge_magic(void)
+{
+       struct pci_dev *pci = NULL;
+       u32 tmp;
+
+       for (;;) {
+               /* If there is any Pericom PI7C9X110 PCI-E/PCI bridge ... */
+               pci = pci_get_device(0x12d8, 0xe110, pci);
+               if (!pci)
+                       break;
+               /*
+                * ... configure its secondary internal arbiter to park to
+                * the secondary port, instead of to the last master.
+                */
+               if (!pci_read_config_dword(pci, 0x40, &tmp)) {
+                       tmp |= 1;
+                       pci_write_config_dword(pci, 0x40, tmp);
+               }
+               /* Why?  Try asking C-Media. */
+       }
+}
+
 static void oxygen_init(struct oxygen *chip)
 {
        unsigned int i;
@@ -585,6 +607,7 @@ int oxygen_pci_probe(struct pci_dev *pci, int index, char *id,
        snd_card_set_dev(card, &pci->dev);
        card->private_free = oxygen_card_free;
 
+       pci_bridge_magic();
        oxygen_init(chip);
        chip->model.init(chip);