4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai <tiwai@xxxxxxx> [ Upstream commit 78c9be61c3a5cd9e2439fd27a5ffad73a81958c7 ] Introduce a new flag, uc_buffer, to indicate that the controller requires the non-cached pages for stream buffers, either as a chip-specific requirement or specified via snoop=0 option. This improves the code-readability. Also, this patch fixes the incorrect behavior for C-Media chip where the stream buffers were never handled as non-cached due to the check of driver_type even if you pass snoop=0 option. Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/pci/hda/hda_controller.h | 1 + sound/pci/hda/hda_intel.c | 11 ++++++++--- 2 files changed, 9 insertions(+), 3 deletions(-) --- a/sound/pci/hda/hda_controller.h +++ b/sound/pci/hda/hda_controller.h @@ -151,6 +151,7 @@ struct azx { unsigned int msi:1; unsigned int probing:1; /* codec probing phase */ unsigned int snoop:1; + unsigned int uc_buffer:1; /* non-cached pages for stream buffers */ unsigned int align_buffer_size:1; unsigned int region_requested:1; unsigned int disabled:1; /* disabled by vga_switcheroo */ --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -401,7 +401,7 @@ static void __mark_pages_wc(struct azx * #ifdef CONFIG_SND_DMA_SGBUF if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_SG) { struct snd_sg_buf *sgbuf = dmab->private_data; - if (chip->driver_type == AZX_DRIVER_CMEDIA) + if (!chip->uc_buffer) return; /* deal with only CORB/RIRB buffers */ if (on) set_pages_array_wc(sgbuf->page_table, sgbuf->pages); @@ -1538,6 +1538,7 @@ static void azx_check_snoop_available(st dev_info(chip->card->dev, "Force to %s mode by module option\n", snoop ? "snoop" : "non-snoop"); chip->snoop = snoop; + chip->uc_buffer = !snoop; return; } @@ -1558,8 +1559,12 @@ static void azx_check_snoop_available(st snoop = false; chip->snoop = snoop; - if (!snoop) + if (!snoop) { dev_info(chip->card->dev, "Force to non-snoop mode\n"); + /* C-Media requires non-cached pages only for CORB/RIRB */ + if (chip->driver_type != AZX_DRIVER_CMEDIA) + chip->uc_buffer = true; + } } static void azx_probe_work(struct work_struct *work) @@ -1958,7 +1963,7 @@ static void pcm_mmap_prepare(struct snd_ #ifdef CONFIG_X86 struct azx_pcm *apcm = snd_pcm_substream_chip(substream); struct azx *chip = apcm->chip; - if (!azx_snoop(chip) && chip->driver_type != AZX_DRIVER_CMEDIA) + if (chip->uc_buffer) area->vm_page_prot = pgprot_writecombine(area->vm_page_prot); #endif }