[PATCH 4.9 071/141] ALSA: hda: Check the non-cached stream buffers more explicitly

Greg Kroah-Hartman
2018-11-11T22:42:37Z

From: Takashi Iwai <tiwai@suse.de>

[ 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@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -155,6 +155,7 @@ 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
@@ -410,7 +410,7 @@ 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);
@@ -1503,6 +1503,7 @@ 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;
}

@@ -1523,8 +1524,12 @@ 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)
@@ -1947,7 +1952,7 @@ 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
}