more stability fixes

us144mkii.c

@@ -332,6 +332,7 @@ static int tascam_suspend(struct usb_interface *intf, pm_message_t message) {
   cancel_work_sync(&tascam->capture_work);
   cancel_work_sync(&tascam->midi_in_work);
   cancel_work_sync(&tascam->midi_out_work);
+  cancel_work_sync(&tascam->stop_pcm_work);
   usb_kill_anchored_urbs(&tascam->playback_anchor);
   usb_kill_anchored_urbs(&tascam->capture_anchor);
   usb_kill_anchored_urbs(&tascam->feedback_anchor);
@@ -494,6 +495,7 @@ static int tascam_probe(struct usb_interface *intf,
   timer_setup(&tascam->error_timer, tascam_error_timer, 0);
 
   INIT_WORK(&tascam->stop_work, tascam_stop_work_handler);
+  INIT_WORK(&tascam->stop_pcm_work, tascam_stop_pcm_work_handler);
 
   if (kfifo_alloc(&tascam->midi_in_fifo, MIDI_IN_FIFO_SIZE, GFP_KERNEL)) {
     snd_card_free(card);
@@ -576,6 +578,7 @@ static void tascam_disconnect(struct usb_interface *intf) {
     cancel_work_sync(&tascam->capture_work);
     cancel_work_sync(&tascam->midi_in_work);
     cancel_work_sync(&tascam->midi_out_work);
+    cancel_work_sync(&tascam->stop_pcm_work);
 
     usb_kill_anchored_urbs(&tascam->playback_anchor);
     usb_kill_anchored_urbs(&tascam->capture_anchor);

us144mkii.h

@@ -258,6 +258,7 @@ struct tascam_card {
   // Work structs
   struct work_struct capture_work;
   struct work_struct stop_work;
+  struct work_struct stop_pcm_work;
   struct work_struct midi_in_work;
   struct work_struct midi_out_work;
 
@@ -310,6 +311,15 @@ int tascam_alloc_urbs(struct tascam_card *tascam);
  */
 void tascam_stop_work_handler(struct work_struct *work);
 
+/**
+ * tascam_stop_pcm_work_handler() - Work handler to stop PCM streams.
+ * @work: Pointer to the work_struct.
+ *
+ * This function is scheduled to stop PCM streams (playback and capture)
+ * from a workqueue context, avoiding blocking operations in interrupt context.
+ */
+void tascam_stop_pcm_work_handler(struct work_struct *work);
+
 /* us144mkii_pcm.h */
 #include "us144mkii_pcm.h"
 

us144mkii_playback.c

@@ -343,10 +343,7 @@ void feedback_urb_complete(struct urb *urb) {
               FEEDBACK_SYNC_LOSS_THRESHOLD) {
             dev_err(tascam->card->dev,
                     "Fatal: Feedback sync lost. Stopping stream.\n");
-            if (playback_ss)
+            schedule_work(&tascam->stop_pcm_work);
-              snd_pcm_stop(playback_ss, SNDRV_PCM_STATE_XRUN);
-            if (capture_ss)
-              snd_pcm_stop(capture_ss, SNDRV_PCM_STATE_XRUN);
             tascam->feedback_synced = false;
             goto continue_unlock;
           }
@@ -427,3 +424,20 @@ continue_unlock:
 out:
   usb_put_urb(urb);
 }
+
+/**
+ * tascam_stop_pcm_work_handler() - Work handler to stop PCM streams.
+ * @work: Pointer to the work_struct.
+ *
+ * This function is scheduled to stop PCM streams (playback and capture)
+ * from a workqueue context, avoiding blocking operations in interrupt context.
+ */
+void tascam_stop_pcm_work_handler(struct work_struct *work) {
+  struct tascam_card *tascam =
+      container_of(work, struct tascam_card, stop_pcm_work);
+
+  if (tascam->playback_substream)
+    snd_pcm_stop(tascam->playback_substream, SNDRV_PCM_STATE_XRUN);
+  if (tascam->capture_substream)
+    snd_pcm_stop(tascam->capture_substream, SNDRV_PCM_STATE_XRUN);
+}