Re: [PATCH v2] drm/amdgpu: add dce6 drm_panic support

[Jocelyn Falempe]

On 12/08/2024 08:09, Lu Yao wrote:
Add support for the drm_panic module, which displays a pretty user
friendly message on the screen when a Linux kernel panic occurs.

From a drm_panic point of view, it looks good to me.
I don't have the required hardware, so unfortunately I wasn't able to 
test it.

Best regards,

--

Jocelyn



Signed-off-by: Lu Yao <ya...@kylinos.cn>
---
Changes in v2:
1. Drop include "drm_internal.h"
2. Add disabling DC tiling ops.
Per suggestion from previous thread:
https://patchwork.freedesktop.org/patch/606879/?series=136832&rev=1
---
  drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 48 +++++++++++++++++++++++++++
  1 file changed, 48 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c 
b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
index 05c0df97f01d..ba1b7a36caa3 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
@@ -28,6 +28,7 @@
  #include <drm/drm_modeset_helper.h>
  #include <drm/drm_modeset_helper_vtables.h>
  #include <drm/drm_vblank.h>
+#include <drm/drm_panic.h>
  
  #include "amdgpu.h"
  #include "amdgpu_pm.h"
@@ -2600,6 +2601,52 @@ static const struct drm_crtc_helper_funcs 
dce_v6_0_crtc_helper_funcs = {
        .get_scanout_position = amdgpu_crtc_get_scanout_position,
  };
  
+static int dce_v6_0_drm_primary_plane_get_scanout_buffer(struct drm_plane *plane,
+                                                        struct 
drm_scanout_buffer *sb)
+{
+       struct drm_framebuffer *fb;
+       struct amdgpu_bo *abo;
+       struct amdgpu_crtc *amdgpu_crtc;
+       struct amdgpu_device *adev;
+       uint32_t fb_format;
+
+       if (!plane->fb)
+               return -EINVAL;
+
+       fb = plane->fb;
+
+       abo = gem_to_amdgpu_bo(fb->obj[0]);
+       amdgpu_crtc = to_amdgpu_crtc(plane->crtc);
+       adev = drm_to_adev(fb->dev);
+
+       if (!abo->kmap.virtual &&
+           ttm_bo_kmap(&abo->tbo, 0, PFN_UP(abo->tbo.base.size), &abo->kmap)) {
+               DRM_WARN("amdgpu bo map failed, panic won't be displayed\n");
+               return -ENOMEM;
+       }
+
+       if (abo->kmap.bo_kmap_type & TTM_BO_MAP_IOMEM_MASK)
+               iosys_map_set_vaddr_iomem(&sb->map[0], abo->kmap.virtual);
+       else
+               iosys_map_set_vaddr(&sb->map[0], abo->kmap.virtual);
+
+       sb->width = fb->width;
+       sb->height = fb->height;
+       sb->format = fb->format;
+       sb->pitch[0] = fb->pitches[0];
+
+       /* Disable DC tiling */
+       fb_format = RREG32(mmGRPH_CONTROL + amdgpu_crtc->crtc_offset);
+       fb_format &= ~GRPH_ARRAY_MODE(0x7);
+       WREG32(mmGRPH_CONTROL + amdgpu_crtc->crtc_offset, fb_format);
+
+       return 0;
+}
+
+static const struct drm_plane_helper_funcs 
dce_v6_0_drm_primary_plane_helper_funcs = {
+       .get_scanout_buffer = dce_v6_0_drm_primary_plane_get_scanout_buffer
+};
+
  static int dce_v6_0_crtc_init(struct amdgpu_device *adev, int index)
  {
        struct amdgpu_crtc *amdgpu_crtc;
@@ -2627,6 +2674,7 @@ static int dce_v6_0_crtc_init(struct amdgpu_device *adev, 
int index)
        amdgpu_crtc->encoder = NULL;
        amdgpu_crtc->connector = NULL;
        drm_crtc_helper_add(&amdgpu_crtc->base, &dce_v6_0_crtc_helper_funcs);
+       drm_plane_helper_add(amdgpu_crtc->base.primary, 
&dce_v6_0_drm_primary_plane_helper_funcs);
  
  	return 0;
  }