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

[Jocelyn Falempe <jfalempe@redhat.com>]

On 17/09/2024 15:21, Alex Deucher wrote:
> On Mon, Aug 12, 2024 at 2:10 AM Lu Yao <yaolu@kylinos.cn> wrote:
>>
>> Add support for the drm_panic module, which displays a pretty user
>> friendly message on the screen when a Linux kernel panic occurs.
>>
>> Signed-off-by: Lu Yao <yaolu@kylinos.cn>
> 
> Patch looks good to me.  Any chance you want to convert the other
> non-DC dce files (dce_v8_0.c, dce_v10_0.c, dce_v11_0.c) while you are
> at it?

I've made a similar patch in amdgpu_dm_plane.c, and it works on a Radeon 
pro w6400.
But it only works when I'm in a VT terminal (so the framebuffer is 
linear and CPU accessible).
When under Gnome/Wayland, the flag AMDGPU_GEM_CREATE_NO_CPU_ACCESS is 
set, so that means I can't vmap it ?

Also I don't know if there is a similar way to disable 
tiling/compression on this hardware.

Best regards,

-- 

Jocelyn


> 
> Alex
> 
> 
>> ---
>> 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;
>>   }
>> --
>> 2.25.1
>>
>