ALSA: hda - Workaround for crackled sound on AMD controller (1022:1457)

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@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c
index 2fbdde2399362677000a581a16fb0defce504fac..48d863736b3c32ed7da2d29ab73da0b741b08fdc 100644 (file)
--- a/sound/pci/hda/hda_controller.c
+++ b/sound/pci/hda/hda_controller.c
@@ -613,6 +613,13 @@ static int azx_pcm_open(struct snd_pcm_substream *substream)
                                     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

diff --git a/sound/pci/hda/hda_controller.h b/sound/pci/hda/hda_controller.h
index baa15374fbcb4a38301fa7d5a5197a04ecb66e1b..f2a6df5e6bcb72cf222e40efda3bc2adabe66146 100644 (file)
--- a/sound/pci/hda/hda_controller.h
+++ b/sound/pci/hda/hda_controller.h
@@ -31,7 +31,7 @@
 /* 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 */

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 1e14d7270adf6d70474283bf92cb9ed441e7fe76..a6d8c0d77b8466c06006c33860384e07c911cb74 100644 (file)
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -64,6 +64,7 @@ enum {
        POS_FIX_VIACOMBO,
        POS_FIX_COMBO,
        POS_FIX_SKL,
+       POS_FIX_FIFO,
 };
 
 /* Defines for ATI HD Audio support in SB450 south bridge */
@@ -135,7 +136,7 @@ module_param_array(model, charp, NULL, 0444);
 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);
@@ -332,6 +333,11 @@ 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 |\
@@ -841,6 +847,49 @@ static unsigned int azx_via_get_position(struct azx *chip,
        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)
 {
@@ -1417,6 +1466,7 @@ static int check_position_fix(struct azx *chip, int fix)
        case POS_FIX_VIACOMBO:
        case POS_FIX_COMBO:
        case POS_FIX_SKL:
+       case POS_FIX_FIFO:
                return fix;
        }
 
@@ -1433,6 +1483,10 @@ static int check_position_fix(struct azx *chip, int fix)
                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;
@@ -1453,6 +1507,7 @@ static void assign_position_fix(struct azx *chip, int fix)
                [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];
@@ -1467,6 +1522,9 @@ static void assign_position_fix(struct azx *chip, int fix)
                        azx_get_delay_from_lpib;
        }
 
+       if (fix == POS_FIX_FIFO)
+               chip->get_delay[0] = chip->get_delay[1] =
+                       azx_get_delay_from_fifo;
 }
 
 /*
@@ -2447,6 +2505,9 @@ static const struct pci_device_id azx_ids[] = {
        /* 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 |