From 7189eb9b8f7962474956196c301676470542f253 Mon Sep 17 00:00:00 2001 From: Mengdong Lin Date: Tue, 13 May 2014 16:57:08 +0800 Subject: [PATCH] ALSA: hda - mask buggy stream DMA0 for Broadwell display controller 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 by keeping it as opened. This is a tentative workaround, so keep the change small as Takashi suggested. Signed-off-by: Mengdong Lin Signed-off-by: Takashi Iwai --- sound/pci/hda/hda_intel.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index b540ad71eb0d..2c54629d62d1 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1367,6 +1367,12 @@ static int azx_first_init(struct azx *chip) /* initialize streams */ azx_init_stream(chip); + /* workaround for Broadwell HDMI: the first stream is broken, + * so mask it by keeping it as if opened + */ + if (pci->vendor == 0x8086 && pci->device == 0x160c) + chip->azx_dev[0].opened = 1; + /* initialize chip */ azx_init_pci(chip); azx_init_chip(chip, (probe_only[dev] & 2) == 0); -- 2.20.1