From 56552cc6b382167f8c4730f293c640361aec8de2 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Sat, 21 Mar 2026 13:20:13 +0100
Subject: [PATCH] drivers/graphics/ihdgd: Introduce helpers to fetch current
 plane state

---
 drivers/graphics/ihdgd/src/device/mod.rs  | 30 ++---------------
 drivers/graphics/ihdgd/src/device/pipe.rs | 40 +++++++++++++++++++++++
 2 files changed, 43 insertions(+), 27 deletions(-)

diff --git a/drivers/graphics/ihdgd/src/device/mod.rs b/drivers/graphics/ihdgd/src/device/mod.rs
index 43a982d731..e45a2d1b6e 100644
--- a/drivers/graphics/ihdgd/src/device/mod.rs
+++ b/drivers/graphics/ihdgd/src/device/mod.rs
@@ -432,34 +432,10 @@ impl Device {
         for pipe in self.pipes.iter() {
             for plane in pipe.planes.iter() {
                 if plane.ctl.readf(PLANE_CTL_ENABLE) {
-                    let buf_cfg = plane.buf_cfg.read();
-                    let buffer_start = buf_cfg & 0x7FF;
-                    let buffer_end = (buf_cfg >> 16) & 0x7FF;
-                    self.alloc_buffers
-                        .allocate_exact_range(buffer_start..(buffer_end + 1))
-                        .unwrap_or_else(|err| {
-                            panic!(
-                                "failed to allocate pre-existing buffer blocks {} to {}: {:?}",
-                                buffer_start, buffer_end, err
-                            );
-                        });
+                    plane.fetch_modeset(&mut self.alloc_buffers);
 
-                    let size = plane.size.read();
-                    let width = (size & 0xFFFF) + 1;
-                    let height = ((size >> 16) & 0xFFFF) + 1;
-                    let stride_16 = plane.stride.read() & 0x7FF;
-                    //TODO: this will be wrong for tiled planes
-                    let stride = stride_16 * 16;
-                    let surf = plane.surf.read() & 0xFFFFF000;
-                    //TODO: read bits per pixel
-                    let surf_size = (stride * height * 4).next_multiple_of(4096);
-                    self.alloc_surfaces.allocate_exact_range(surf .. (surf + surf_size)).unwrap_or_else(|err| {
-                        panic!("failed to allocate pre-existing surface at 0x{:x} of size {}: {:?}", surf, surf_size, err);
-                    });
-
-                    self.framebuffers.push(unsafe {
-                        DeviceFb::new(&self.gm, surf, width, height, stride, false)
-                    });
+                    self.framebuffers
+                        .push(plane.fetch_framebuffer(&self.gm, &mut self.alloc_surfaces));
                 }
             }
         }
diff --git a/drivers/graphics/ihdgd/src/device/pipe.rs b/drivers/graphics/ihdgd/src/device/pipe.rs
index 15d3232bf4..4d326310ab 100644
--- a/drivers/graphics/ihdgd/src/device/pipe.rs
+++ b/drivers/graphics/ihdgd/src/device/pipe.rs
@@ -64,6 +64,20 @@ pub struct Plane {
 }
 
 impl Plane {
+    pub fn fetch_modeset(&self, alloc_buffers: &mut RangeAllocator<u32>) {
+        let buf_cfg = self.buf_cfg.read();
+        let buffer_start = buf_cfg & 0x7FF;
+        let buffer_end = (buf_cfg >> 16) & 0x7FF;
+        alloc_buffers
+            .allocate_exact_range(buffer_start..(buffer_end + 1))
+            .unwrap_or_else(|err| {
+                panic!(
+                    "failed to allocate pre-existing buffer blocks {} to {}: {:?}",
+                    buffer_start, buffer_end, err
+                );
+            });
+    }
+
     pub fn modeset(&mut self, alloc_buffers: &mut RangeAllocator<u32>) -> syscall::Result<()> {
         // FIXME handle runtime buffer reconfiguration
         //TODO: enable DBUF if more buffers needed
@@ -90,6 +104,32 @@ impl Plane {
         Ok(())
     }
 
+    pub fn fetch_framebuffer(
+        &self,
+        gm: &MmioRegion,
+        alloc_surfaces: &mut RangeAllocator<u32>,
+    ) -> DeviceFb {
+        let size = self.size.read();
+        let width = (size & 0xFFFF) + 1;
+        let height = ((size >> 16) & 0xFFFF) + 1;
+        let stride_16 = self.stride.read() & 0x7FF;
+        //TODO: this will be wrong for tiled planes
+        let stride = stride_16 * 16;
+        let surf = self.surf.read() & 0xFFFFF000;
+        //TODO: read bits per pixel
+        let surf_size = (stride * height * 4).next_multiple_of(4096);
+        alloc_surfaces
+            .allocate_exact_range(surf..(surf + surf_size))
+            .unwrap_or_else(|err| {
+                panic!(
+                    "failed to allocate pre-existing surface at 0x{:x} of size {}: {:?}",
+                    surf, surf_size, err
+                );
+            });
+
+        unsafe { DeviceFb::new(gm, surf, width, height, stride, true) }
+    }
+
     pub fn set_framebuffer(&mut self, fb: &DeviceFb) {
         //TODO: documentation on this is not great
         let stride_16 = fb.stride / 16;