snd/hda: Restore the magic register setting to enable cache snooping

It looks like certain chips ignore NOSNOOP settings in PCIe device
control configuration register.  Restore the magic register setting
to enable cache snooping.

Reported-by: many
Tested-by: Goetz Isenmann <info@goetz-isenmann.de>

diff --git a/sys/dev/sound/pci/hda/hdac.c b/sys/dev/sound/pci/hda/hdac.c
index 8767349..88fa5e6 100644 (file)
--- a/sys/dev/sound/pci/hda/hdac.c
+++ b/sys/dev/sound/pci/hda/hdac.c
@@ -3814,7 +3814,6 @@ hdac_attach(device_t dev)
        sc->flags &= ~HDAC_F_DMA_NOCACHE;
 #endif
 
-#if 0
                /*
                 * Try to enable PCIe snoop to avoid messing around with
                 * uncacheable DMA attribute. Since PCIe snoop register
@@ -3852,7 +3851,6 @@ hdac_attach(device_t dev)
                        }
                        break;
                }
-#endif
 
                if (pci_is_pcie(dev)) {
                        int pcie_cap = pci_get_pciecap_ptr(dev);