us144mkii_capture.c

@@ -1,14 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0-only
 // Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
 
-#include <linux/types.h>
-#include <linux/unaligned/packed_struct.h>
-#include <asm/byteorder.h>
+#include <asm/unaligned.h>
 #include "us144mkii_pcm.h"
 
-#define get_unaligned_le64(ptr)	le64_to_cpu(__get_unaligned_cpu64(ptr))
-#define put_unaligned_le32(val, ptr) __put_unaligned_cpu32((val), ptr)
-
 const struct snd_pcm_hardware tascam_capture_hw = {
 	.info = (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
 	SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP_VALID |

us144mkii_pcm.c

@@ -128,7 +128,6 @@ int tascam_pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_
 	usb_kill_anchored_urbs(&tascam->feedback_anchor);
 	usb_kill_anchored_urbs(&tascam->capture_anchor);
 	atomic_set(&tascam->active_urbs, 0);
-	tascam->running_ghost_playback = false;
 
 	u16 stream_mode = (tascam->dev_id == USB_PID_TASCAM_US200) ? MODE_VAL_STREAM_START_US200 : MODE_VAL_STREAM_START;
 	err = us144mkii_configure_device_for_rate(tascam, rate, stream_mode);

us144mkii_playback.c

@@ -130,6 +130,8 @@ static int tascam_playback_close(struct snd_pcm_substream *substream)
 {
 	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
 	atomic_set(&tascam->playback_active, 0);
+	usb_kill_anchored_urbs(&tascam->playback_anchor);
+	usb_kill_anchored_urbs(&tascam->feedback_anchor);
 	tascam->playback_substream = NULL;
 	return 0;
 }
@@ -138,21 +140,18 @@ static int tascam_playback_prepare(struct snd_pcm_substream *substream)
 {
 	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
 
+	usb_kill_anchored_urbs(&tascam->playback_anchor);
+	usb_kill_anchored_urbs(&tascam->feedback_anchor);
+
 	tascam->driver_playback_pos = 0;
 	tascam->playback_frames_consumed = 0;
 	tascam->last_pb_period_pos = 0;
 	tascam->feedback_synced = false;
-
-	if (tascam->running_ghost_playback)
-		return 0;
-
-	usb_kill_anchored_urbs(&tascam->playback_anchor);
-	usb_kill_anchored_urbs(&tascam->feedback_anchor);
-
+	tascam->running_ghost_playback = false;
 	tascam->feedback_urb_skip_count = 4;
 	tascam->phase_accum = 0;
 	tascam->freq_q16 = div_u64(((u64)tascam->current_rate << 16), 8000);
-	tascam->running_ghost_playback = false;
+
 	prepare_urb_descriptors(tascam);
 	return 0;
 }
@@ -182,7 +181,9 @@ static int tascam_playback_trigger(struct snd_pcm_substream *substream, int cmd)
 		case SNDRV_PCM_TRIGGER_SUSPEND:
 		case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 			atomic_set(&tascam->playback_active, 0);
-			tascam->running_ghost_playback = true;
+			/* Fall back to ghost playback if capture/midi active */
+			if (atomic_read(&tascam->stream_refs) > 0)
+				tascam->running_ghost_playback = true;
 		break;
 		default:
 			ret = -EINVAL;
@@ -198,15 +199,8 @@ static snd_pcm_uframes_t tascam_playback_pointer(struct snd_pcm_substream *subst
 	unsigned long flags;
 	u64 pos;
 
-	if (!atomic_read(&tascam->playback_active)) {
-		if (tascam->running_ghost_playback) {
-			spin_lock_irqsave(&tascam->lock, flags);
-			pos = tascam->playback_frames_consumed;
-			spin_unlock_irqrestore(&tascam->lock, flags);
-			return (snd_pcm_uframes_t)pos;
-		}
+	if (!atomic_read(&tascam->playback_active))
 		return 0;
-	}
 
 	spin_lock_irqsave(&tascam->lock, flags);
 	pos = tascam->playback_frames_consumed;
@@ -256,22 +250,6 @@ void playback_urb_complete(struct urb *urb)
 	}
 	urb->transfer_buffer_length = total_bytes;
 
-	/* A stuck PLL can produce all-zero-length packets, which makes the
-	 * device underflow and output persistent noise. Force a minimal
-	 * nominal packet if that happens.
-	 */
-	if (total_bytes == 0) {
-		tascam->freq_q16 = div_u64(((u64)tascam->current_rate << 16), 8000);
-		tascam->phase_accum = 0;
-		frames = min((u32)(tascam->current_rate / 8000), (u32)MAX_FRAMES_PER_PACKET);
-		if (frames == 0)
-			frames = 1;
-		urb->iso_frame_desc[0].offset = 0;
-		urb->iso_frame_desc[0].length = frames * PLAYBACK_FRAME_SIZE;
-		total_bytes = urb->iso_frame_desc[0].length;
-		urb->transfer_buffer_length = total_bytes;
-	}
-
 	/* Ghost Playback: Send Silence */
 	if (!atomic_read(&tascam->playback_active)) {
 		if (tascam->running_ghost_playback) {
@@ -358,22 +336,9 @@ void feedback_urb_complete(struct urb *urb)
 				u8 *d = urb->transfer_buffer + urb->iso_frame_desc[p].offset;
 				u32 val = (urb->iso_frame_desc[p].actual_length >= 3) ? (d[0] + d[1] + d[2]) : (d[0] * 3);
 				u32 target = (val << 16) / 24;
-				u32 nominal = div_u64(((u64)tascam->current_rate << 16), 8000);
-				u32 min_freq = nominal - (nominal >> 2);
-				u32 max_freq = nominal + (nominal >> 2);
-
-				/* Ignore transient bad feedback that would drive the PLL to
-				 * zero or an unrealistic value and cause DAC underflow noise.
-				 */
-				if (tascam->current_rate > 0 && target >= min_freq && target <= max_freq) {
-					tascam->freq_q16 = (tascam->freq_q16 * PLL_FILTER_OLD_WEIGHT +
-					    target * PLL_FILTER_NEW_WEIGHT) / PLL_FILTER_DIVISOR;
-					if (tascam->freq_q16 < min_freq)
-						tascam->freq_q16 = min_freq;
-					else if (tascam->freq_q16 > max_freq)
-						tascam->freq_q16 = max_freq;
-					tascam->feedback_synced = true;
-				}
+				tascam->freq_q16 = (tascam->freq_q16 * PLL_FILTER_OLD_WEIGHT +
+				target * PLL_FILTER_NEW_WEIGHT) / PLL_FILTER_DIVISOR;
+				tascam->feedback_synced = true;
 			}
 		}
 	}