minor scanvideo_dpi fixes

src/rp2_common/pico_audio_i2s/audio_i2s.c

@@ -216,8 +216,6 @@ bool audio_i2s_connect_extra(audio_buffer_pool_t *producer, bool buffer_on_give,
             printf("Copying stereo to stereo at %d Hz\n", (int) producer->format->sample_freq);
 #endif
 #endif
-            // todo we should support pass thru option anyway
-            printf("TODO... not completing stereo audio connection properly!\n");
         } else {
 #if PICO_AUDIO_I2S_MONO_OUTPUT
             printf("Copying mono to mono at %d Hz\n", (int) producer->format->sample_freq);

src/rp2_common/pico_scanvideo_dpi/scanvideo.c

@@ -130,6 +130,8 @@ CU_REGISTER_DEBUG_PINS(video_timing, video_dma_buffer, video_irq, video_dma_comp
 
 // ======================
 
+#define GENERATING_LIST 1
+//#define PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS 1
 #if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS
 // we want some sort of assertion even in release builds
 #ifndef NDEBUG
@@ -260,7 +262,7 @@ static struct {
         // locks (i.e. we are saving an extra lock in the latch case by not placing in a separate struct)
         full_scanline_buffer_t *generated_ascending_scanline_id_list;
         full_scanline_buffer_t *generated_ascending_scanline_id_list_tail;
-#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS
+#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS && GENERATING_LIST
         full_scanline_buffer_t *generating_list;
 #endif
     } scanline;
@@ -383,6 +385,7 @@ inline static full_scanline_buffer_t *list_remove_head_ascending(full_scanline_b
     full_scanline_buffer_t *fsb = *phead;
 
     if (fsb) {
+        scanline_assert(*ptail);
         *phead = fsb->next;
 
         if (!fsb->next) {
@@ -556,6 +559,28 @@ static inline void release_scanline_irqs_enabled(int buffers_to_free_count,
     }
 }
 
+// Note that this is not a general purpose function. It must be called by a caller
+// who can guarantee that a DMA completion IRQ will not be taken during this method
+static inline void abort_all_dma_channels_assuming_no_irq_preemption() {
+    // the reason the above requirements are in place is that the DMA controller may cause
+    // a completion IRQ during (or immediately the abort). There are *slower* ways to
+    // work around it in software, but we want to suppress the IRQ afterwards anyway, so
+    // as long as the spurious IRQ doesn't get taken here, then the h/w issue is of no problem
+    dma_hw->abort = PICO_SCANVIDEO_SCANLINE_DMA_CHANNELS_MASK;
+    // note that relying on the abort bits is no longer safe, as it may get cleared before the spurious IRQ happens
+    //    // wait for abort(s) to complete
+    //    while (dma_hw->abort & PICO_SCANVIDEO_SCANLINE_DMA_CHANNELS_MASK) tight_loop_contents();
+    while (dma_channel_is_busy(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL)) tight_loop_contents();
+#if PICO_SCANVIDEO_PLANE_COUNT > 1
+    while (dma_channel_is_busy(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL2)) tight_loop_contents();
+#if PICO_SCANVIDEO_PLANE_COUNT > 2
+    while (dma_channel_is_busy(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL3)) tight_loop_contents();
+#endif
+#endif
+    // we don't want any pending completion IRQ which may have happened in the interim
+    dma_hw->ints0 = PICO_SCANVIDEO_SCANLINE_DMA_CHANNELS_MASK;
+}
+
 static inline bool update_dma_transfer_state_irqs_enabled(bool cancel_if_not_complete,
                                                           int *scanline_buffers_to_release) {
     uint32_t save = spin_lock_blocking(shared_state.dma.lock);
@@ -609,13 +634,9 @@ static inline bool update_dma_transfer_state_irqs_enabled(bool cancel_if_not_com
             shared_state.dma.buffers_to_release = 0;
             DEBUG_PINS_XOR(video_in_use, 4);
         }
-        dma_channel_abort(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL);
-#if PICO_SCANVIDEO_PLANE_COUNT > 1
-        dma_channel_abort(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL2);
-#if PICO_SCANVIDEO_PLANE_COUNT > 2
-        dma_channel_abort(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL3);
-#endif
-#endif
+        // note that we guarantee no IRQ preemption because this method is always called within some
+        // type of video IRQ handle, and of those the DMA IRQ is the lowest priority.
+        abort_all_dma_channels_assuming_no_irq_preemption();
 #else
         panic("need VIDEO_RECOVERY");
 #endif
@@ -627,13 +648,9 @@ static inline bool update_dma_transfer_state_irqs_enabled(bool cancel_if_not_com
         shared_state.dma.scanline_in_progress = 0;
         *scanline_buffers_to_release = shared_state.dma.buffers_to_release;
         shared_state.dma.buffers_to_release = 0;
-        dma_abort(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL);
-#if PICO_SCANVIDEO_PLANE_COUNT > 1
-        dma_abort(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL2);
-#if PICO_SCANVIDEO_PLANE_COUNT > 2
-        dma_channel_abort(PICO_SCANVIDEO_SCANLINE_DMA_CHANNEL3);
-#endif
-#endif
+        // note that we guarantee no IRQ preemption because this method is always called within some
+        // type of video IRQ handle, and of those the DMA IRQ is the lowest priority.
+        abort_all_dma_channels_assuming_no_irq_preemption();
     }
     spin_unlock(shared_state.dma.lock, save);
     return false;
@@ -797,8 +814,9 @@ void __video_most_time_critical_func(prepare_for_active_scanline_irqs_enabled)()
         shared_state.scanline.current_scanline_buffer = NULL;
 #if PICO_SCANVIDEO_LINKED_SCANLINE_BUFFERS
     } else if (fsb->core.link_after && !--fsb->core.link_after) {
-        assert(fsb->core.link);
+        scanline_assert(fsb->core.link);
         spin_lock_unsafe_blocking(shared_state.in_use.lock);
+        scanline_assert(fsb->core.link);
         DEBUG_PINS_SET(video_link, 1);
         full_scanline_buffer_t *fsb2 = (full_scanline_buffer_t *)fsb->core.link;
         fsb->core.link = NULL; // the linkee scanline is now tracked on its own, so shouldn't be freed with the linker
@@ -1046,7 +1064,7 @@ extern bool scanvideo_in_vblank() {
     return *(volatile bool *) &shared_state.scanline.in_vblank;
 }
 
-static uint default_scanvideo_scanline_repeat_count_fn(uint32_t scanline_id) {
+static uint __no_inline_not_in_flash_func(default_scanvideo_scanline_repeat_count_fn)(uint32_t scanline_id) {
     return 1;
 }
 
@@ -1066,7 +1084,7 @@ extern scanvideo_scanline_buffer_t *__video_time_critical_func(scanvideo_begin_s
         if (fsb) {
             save = spin_lock_blocking(shared_state.scanline.lock);
             DEBUG_PINS_SET(video_timing, 1);
-#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS
+#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS && GENERATING_LIST
             list_prepend(&shared_state.scanline.generating_list, fsb);
 #endif
             // todo improve this algorithm... how far ahead should we be
@@ -1093,7 +1111,10 @@ extern scanvideo_scanline_buffer_t *__video_time_critical_func(scanvideo_begin_s
     DEBUG_PINS_CLR(video_link, 1);
     DEBUG_PINS_CLR(video_generation, 1);
 #if PICO_SCANVIDEO_LINKED_SCANLINE_BUFFERS
-    fsb->core.link_after = 0;
+    if (fsb) {
+        fsb->core.link = 0;
+        fsb->core.link_after = 0;
+    }
 #endif
     return (scanvideo_scanline_buffer_t *) fsb;
 }
@@ -1129,7 +1150,7 @@ scanvideo_scanline_buffer_t *__video_time_critical_func(scanvideo_begin_scanline
         {
             save = spin_lock_blocking(shared_state.scanline.lock);
             DEBUG_PINS_SET(video_timing, 1);
-#ifdef ENABLE_SCANLINE_ASSERTIONS
+#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS && GENERATING_LIST
             list_prepend(&shared_state.scanline.generating_list, fsb);
             list_prepend(&shared_state.scanline.generating_list, fsb2);
 #endif
@@ -1202,7 +1223,7 @@ scanvideo_scanline_buffer_t *__video_time_critical_func(scanvideo_begin_scanline
             }
             save = spin_lock_blocking(shared_state.scanline.lock);
             DEBUG_PINS_SET(video_timing, 1);
-#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS
+#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS && GENERATING_LIST
             list_prepend(&shared_state.scanline.generating_list, fsb);
 #endif
             // todo improve this algorithm... how far ahead should we be
@@ -1233,7 +1254,7 @@ scanvideo_scanline_buffer_t *__video_time_critical_func(scanvideo_begin_scanline
 
     DEBUG_PINS_CLR(video_link, 1);
     DEBUG_PINS_CLR(video_generation, 1);
-    fsb->core.link_after = 0;
+    if (fsb) fsb->core.link_after = 0;
     return (scanvideo_scanline_buffer_t *) fsb;
 }
 #endif
@@ -1243,7 +1264,7 @@ extern void __video_time_critical_func(scanvideo_end_scanline_generation)(
     DEBUG_PINS_SET(video_generation, 2);
     full_scanline_buffer_t *fsb = (full_scanline_buffer_t *) scanline_buffer;
     uint32_t save = spin_lock_blocking(shared_state.scanline.lock);
-#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS
+#if PICO_SCANVIDEO_ENABLE_SCANLINE_ASSERTIONS && GENERATING_LIST
     list_remove(&shared_state.scanline.generating_list, fsb);
 #endif
     list_insert_ascending(&shared_state.scanline.generated_ascending_scanline_id_list,