[PATCH 4.19 80/91] ALSA: hda - Workaround for crackled sound on AMD controller (1022:1457)

From: Greg Kroah-Hartman
Date: Wed Aug 14 2019 - 13:11:36 EST


From: Takashi Iwai <tiwai@xxxxxxx>

commit c02f77d32d2c45cfb1b2bb99eabd8a78f5ecc7db upstream.

A long-time problem on the recent AMD chip (X370, X470, B450, etc with
PCI ID 1022:1457) with Realtek codecs is the crackled or distorted
sound for capture streams, as well as occasional playback hiccups.
After lengthy debugging sessions, the workarounds we've found are like
the following:

- Set up the proper driver caps for this controller, similar as the
other AMD controller.

- Correct the DMA position reporting with the fixed FIFO size, which
is similar like as workaround used for VIA chip set.

- Even after the position correction, PulseAudio still shows
mysterious stalls of playback streams when a capture is triggered in
timer-scheduled mode. Since we have no clear way to eliminate the
stall, pass the BATCH PCM flag for PA to suppress the tsched mode as
a temporary workaround.

This patch implements the workarounds. For the driver caps, it
defines a new preset, AXZ_DCAPS_PRESET_AMD_SB. It enables the FIFO-
corrected position reporting (corresponding to the new position_fix=6)
and enforces the SNDRV_PCM_INFO_BATCH flag.

Note that the current implementation is merely a workaround.
Hopefully we'll find a better alternative in future, especially about
removing the BATCH flag hack again.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=195303
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
sound/pci/hda/hda_controller.c | 7 ++++
sound/pci/hda/hda_controller.h | 2 -
sound/pci/hda/hda_intel.c | 63 ++++++++++++++++++++++++++++++++++++++++-
3 files changed, 70 insertions(+), 2 deletions(-)

--- a/sound/pci/hda/hda_controller.c
+++ b/sound/pci/hda/hda_controller.c
@@ -624,6 +624,13 @@ static int azx_pcm_open(struct snd_pcm_s
20,
178000000);

+ /* by some reason, the playback stream stalls on PulseAudio with
+ * tsched=1 when a capture stream triggers. Until we figure out the
+ * real cause, disable tsched mode by telling the PCM info flag.
+ */
+ if (chip->driver_caps & AZX_DCAPS_AMD_WORKAROUND)
+ runtime->hw.info |= SNDRV_PCM_INFO_BATCH;
+
if (chip->align_buffer_size)
/* constrain buffer sizes to be multiple of 128
bytes. This is more efficient in terms of memory
--- a/sound/pci/hda/hda_controller.h
+++ b/sound/pci/hda/hda_controller.h
@@ -40,7 +40,7 @@
/* 14 unused */
#define AZX_DCAPS_CTX_WORKAROUND (1 << 15) /* X-Fi workaround */
#define AZX_DCAPS_POSFIX_LPIB (1 << 16) /* Use LPIB as default */
-/* 17 unused */
+#define AZX_DCAPS_AMD_WORKAROUND (1 << 17) /* AMD-specific workaround */
#define AZX_DCAPS_NO_64BIT (1 << 18) /* No 64bit address */
#define AZX_DCAPS_SYNC_WRITE (1 << 19) /* sync each cmd write */
#define AZX_DCAPS_OLD_SSYNC (1 << 20) /* Old SSYNC reg for ICH */
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -78,6 +78,7 @@ enum {
POS_FIX_VIACOMBO,
POS_FIX_COMBO,
POS_FIX_SKL,
+ POS_FIX_FIFO,
};

/* Defines for ATI HD Audio support in SB450 south bridge */
@@ -149,7 +150,7 @@ module_param_array(model, charp, NULL, 0
MODULE_PARM_DESC(model, "Use the given board model.");
module_param_array(position_fix, int, NULL, 0444);
MODULE_PARM_DESC(position_fix, "DMA pointer read method."
- "(-1 = system default, 0 = auto, 1 = LPIB, 2 = POSBUF, 3 = VIACOMBO, 4 = COMBO, 5 = SKL+).");
+ "(-1 = system default, 0 = auto, 1 = LPIB, 2 = POSBUF, 3 = VIACOMBO, 4 = COMBO, 5 = SKL+, 6 = FIFO).");
module_param_array(bdl_pos_adj, int, NULL, 0644);
MODULE_PARM_DESC(bdl_pos_adj, "BDL position adjustment offset.");
module_param_array(probe_mask, int, NULL, 0444);
@@ -350,6 +351,11 @@ enum {
#define AZX_DCAPS_PRESET_ATI_HDMI_NS \
(AZX_DCAPS_PRESET_ATI_HDMI | AZX_DCAPS_SNOOP_OFF)

+/* quirks for AMD SB */
+#define AZX_DCAPS_PRESET_AMD_SB \
+ (AZX_DCAPS_NO_TCSEL | AZX_DCAPS_SYNC_WRITE | AZX_DCAPS_AMD_WORKAROUND |\
+ AZX_DCAPS_SNOOP_TYPE(ATI) | AZX_DCAPS_PM_RUNTIME)
+
/* quirks for Nvidia */
#define AZX_DCAPS_PRESET_NVIDIA \
(AZX_DCAPS_NO_MSI | AZX_DCAPS_CORBRP_SELF_CLEAR |\
@@ -920,6 +926,49 @@ static unsigned int azx_via_get_position
return bound_pos + mod_dma_pos;
}

+#define AMD_FIFO_SIZE 32
+
+/* get the current DMA position with FIFO size correction */
+static unsigned int azx_get_pos_fifo(struct azx *chip, struct azx_dev *azx_dev)
+{
+ struct snd_pcm_substream *substream = azx_dev->core.substream;
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ unsigned int pos, delay;
+
+ pos = snd_hdac_stream_get_pos_lpib(azx_stream(azx_dev));
+ if (!runtime)
+ return pos;
+
+ runtime->delay = AMD_FIFO_SIZE;
+ delay = frames_to_bytes(runtime, AMD_FIFO_SIZE);
+ if (azx_dev->insufficient) {
+ if (pos < delay) {
+ delay = pos;
+ runtime->delay = bytes_to_frames(runtime, pos);
+ } else {
+ azx_dev->insufficient = 0;
+ }
+ }
+
+ /* correct the DMA position for capture stream */
+ if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+ if (pos < delay)
+ pos += azx_dev->core.bufsize;
+ pos -= delay;
+ }
+
+ return pos;
+}
+
+static int azx_get_delay_from_fifo(struct azx *chip, struct azx_dev *azx_dev,
+ unsigned int pos)
+{
+ struct snd_pcm_substream *substream = azx_dev->core.substream;
+
+ /* just read back the calculated value in the above */
+ return substream->runtime->delay;
+}
+
static unsigned int azx_skl_get_dpib_pos(struct azx *chip,
struct azx_dev *azx_dev)
{
@@ -1528,6 +1577,7 @@ static int check_position_fix(struct azx
case POS_FIX_VIACOMBO:
case POS_FIX_COMBO:
case POS_FIX_SKL:
+ case POS_FIX_FIFO:
return fix;
}

@@ -1544,6 +1594,10 @@ static int check_position_fix(struct azx
dev_dbg(chip->card->dev, "Using VIACOMBO position fix\n");
return POS_FIX_VIACOMBO;
}
+ if (chip->driver_caps & AZX_DCAPS_AMD_WORKAROUND) {
+ dev_dbg(chip->card->dev, "Using FIFO position fix\n");
+ return POS_FIX_FIFO;
+ }
if (chip->driver_caps & AZX_DCAPS_POSFIX_LPIB) {
dev_dbg(chip->card->dev, "Using LPIB position fix\n");
return POS_FIX_LPIB;
@@ -1564,6 +1618,7 @@ static void assign_position_fix(struct a
[POS_FIX_VIACOMBO] = azx_via_get_position,
[POS_FIX_COMBO] = azx_get_pos_lpib,
[POS_FIX_SKL] = azx_get_pos_skl,
+ [POS_FIX_FIFO] = azx_get_pos_fifo,
};

chip->get_position[0] = chip->get_position[1] = callbacks[fix];
@@ -1578,6 +1633,9 @@ static void assign_position_fix(struct a
azx_get_delay_from_lpib;
}

+ if (fix == POS_FIX_FIFO)
+ chip->get_delay[0] = chip->get_delay[1] =
+ azx_get_delay_from_fifo;
}

/*
@@ -2594,6 +2652,9 @@ static const struct pci_device_id azx_id
/* AMD Hudson */
{ PCI_DEVICE(0x1022, 0x780d),
.driver_data = AZX_DRIVER_GENERIC | AZX_DCAPS_PRESET_ATI_SB },
+ /* AMD, X370 & co */
+ { PCI_DEVICE(0x1022, 0x1457),
+ .driver_data = AZX_DRIVER_GENERIC | AZX_DCAPS_PRESET_AMD_SB },
/* AMD Stoney */
{ PCI_DEVICE(0x1022, 0x157a),
.driver_data = AZX_DRIVER_GENERIC | AZX_DCAPS_PRESET_ATI_SB |