From: Mengdong Lin mengdong.lin@intel.com

Broadwell display controller has 3 stream DMA engines. DMA0 cannot update DMA postion buffer properly while DMA1 and DMA2 can work well. So this patch masks the buggy DMA0.

Signed-off-by: Mengdong Lin mengdong.lin@intel.com

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 377c3a5..13b13a3 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -281,6 +281,9 @@ static char *driver_short_names[] = { [AZX_DRIVER_GENERIC] = "HD-Audio Generic", };

+#define is_broadwell_controller(pci) \ + ((pci)->vendor == 0x8086 && (pci)->device == 0x160c) + #ifdef CONFIG_X86 static void __mark_pages_wc(struct azx *chip, struct snd_dma_buffer *dmab, bool on) { @@ -1249,6 +1252,7 @@ static int azx_first_init(struct azx *chip) struct snd_card *card = chip->card; int err; unsigned short gcap; + unsigned int stream_mask = 0;

#if BITS_PER_LONG != 64 /* Fix up base address on ULI M5461 */ @@ -1364,7 +1368,10 @@ static int azx_first_init(struct azx *chip) return err;

/* initialize streams */ - azx_init_stream(chip, 0); + if (is_broadwell_controller(pci)) + stream_mask = 0x1; /* mask buggy stream DMA0 */ + + azx_init_stream(chip, stream_mask);

/* initialize chip */ azx_init_pci(chip);