drm/asahi: HACK: Disable compute preemption for now

Possibly because we don't have support in the helper program, this is
broken and causes channel errors. Hack in high priority for now, which
works around it.

Use debug_flags 0x1000000000000 to re-enable for testing.

Signed-off-by: Asahi Lina <lina@asahilina.net>

Author: hoshinolina

drivers/gpu/drm/asahi/fw/channels.rs

@@ -113,7 +113,7 @@ impl TxChannelState for FwCtlChannelState {
     }
 }
 
-#[derive(Debug, Copy, Clone, Default)]
+#[derive(Debug, Copy, Clone, Default, PartialEq, Eq)]
 #[repr(u32)]
 pub(crate) enum PipeType {
     #[default]

drivers/gpu/drm/asahi/fw/workqueue.rs

@@ -98,7 +98,14 @@ pub(crate) mod raw {
 
     #[derive(Debug, Clone, Copy)]
     #[repr(C)]
-    pub(crate) struct Priority(u32, u32, U64, u32, u32, u32);
+    pub(crate) struct Priority(
+        pub(crate) u32,
+        pub(crate) u32,
+        pub(crate) U64,
+        pub(crate) u32,
+        pub(crate) u32,
+        pub(crate) u32,
+    );
 
     pub(crate) const PRIORITY: [Priority; 4] = [
         Priority(0, 0, U64(0xffff_ffff_ffff_0000), 1, 0, 1),

drivers/gpu/drm/asahi/workqueue.rs

@@ -661,6 +661,14 @@ impl WorkQueue::ver {
         let gpu_buf = alloc.private.array_empty_tagged(0x2c18, b"GPBF")?;
         let mut state = alloc.shared.new_default::<RingState>()?;
         let ring = alloc.shared.array_empty(size as usize)?;
+        let mut prio = *raw::PRIORITY.get(priority as usize).ok_or(EINVAL)?;
+
+        if pipe_type == PipeType::Compute && !debug_enabled(DebugFlags::Debug0) {
+            // Hack to disable compute preemption until we fix it
+            prio.0 = 0;
+            prio.5 = 1;
+        }
+
         let inner = WorkQueueInner::ver {
             dev: dev.into(),
             event_manager,
@@ -693,7 +701,7 @@ impl WorkQueue::ver {
                         gpu_rptr2: Default::default(),
                         gpu_rptr3: Default::default(),
                         event_id: AtomicI32::new(-1),
-                        priority: *raw::PRIORITY.get(priority as usize).ok_or(EINVAL)?,
+                        priority: prio,
                         unk_4c: -1,
                         uuid: id as u32,
                         unk_54: -1,