Re: [PATCH v3] drm/amdgpu: register a dirty framebuffer callback for fbcon

[Hamza Mahfooz <hamza.mahfooz@amd.com>]

On 8/23/23 17:47, Mario Limonciello wrote:
> On 8/23/2023 16:44, Hamza Mahfooz wrote:
>> fbcon requires that we implement &drm_framebuffer_funcs.dirty.
>> Otherwise, the framebuffer might take a while to flush (which would
>> manifest as noticeable lag). However, we can't enable this callback for
>> non-fbcon cases since it may cause too many atomic commits to be made at
>> once. So, implement amdgpu_dirtyfb() and only enable it for fbcon
>> framebuffers (we can use the "struct drm_file file" parameter in the
>> callback to check for this since it is only NULL when called by fbcon,
>> at least in the mainline kernel) on devices that support atomic KMS.
>>
>> Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
>> Cc: Mario Limonciello <mario.limonciello@amd.com>
>> Cc: stable@vger.kernel.org # 6.1+
>> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2519
>> Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
>> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> 
> You probably meant to drop Alex's SoB as you bumped v2.  When committing 
> this make sure you drop it.  He can add it when this is upstreamed.

Whoops, ya I'll be sure to drop it.

> 
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
>> -- 
>> v3: check if file is NULL instead of doing a strcmp() and make note of
>>      it in the commit message
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 26 ++++++++++++++++++++-
>>   1 file changed, 25 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
>> index d20dd3f852fc..363e6a2cad8c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
>> @@ -38,6 +38,8 @@
>>   #include <linux/pci.h>
>>   #include <linux/pm_runtime.h>
>>   #include <drm/drm_crtc_helper.h>
>> +#include <drm/drm_damage_helper.h>
>> +#include <drm/drm_drv.h>
>>   #include <drm/drm_edid.h>
>>   #include <drm/drm_fb_helper.h>
>>   #include <drm/drm_gem_framebuffer_helper.h>
>> @@ -532,11 +534,29 @@ bool amdgpu_display_ddc_probe(struct 
>> amdgpu_connector *amdgpu_connector,
>>       return true;
>>   }
>> +static int amdgpu_dirtyfb(struct drm_framebuffer *fb, struct drm_file 
>> *file,
>> +              unsigned int flags, unsigned int color,
>> +              struct drm_clip_rect *clips, unsigned int num_clips)
>> +{
>> +
>> +    if (file)
>> +        return -ENOSYS;
>> +
>> +    return drm_atomic_helper_dirtyfb(fb, file, flags, color, clips,
>> +                     num_clips);
>> +}
>> +
>>   static const struct drm_framebuffer_funcs amdgpu_fb_funcs = {
>>       .destroy = drm_gem_fb_destroy,
>>       .create_handle = drm_gem_fb_create_handle,
>>   };
>> +static const struct drm_framebuffer_funcs amdgpu_fb_funcs_atomic = {
>> +    .destroy = drm_gem_fb_destroy,
>> +    .create_handle = drm_gem_fb_create_handle,
>> +    .dirty = amdgpu_dirtyfb
>> +};
>> +
>>   uint32_t amdgpu_display_supported_domains(struct amdgpu_device *adev,
>>                         uint64_t bo_flags)
>>   {
>> @@ -1139,7 +1159,11 @@ static int 
>> amdgpu_display_gem_fb_verify_and_init(struct drm_device *dev,
>>       if (ret)
>>           goto err;
>> -    ret = drm_framebuffer_init(dev, &rfb->base, &amdgpu_fb_funcs);
>> +    if (drm_drv_uses_atomic_modeset(dev))
>> +        ret = drm_framebuffer_init(dev, &rfb->base,
>> +                       &amdgpu_fb_funcs_atomic);
>> +    else
>> +        ret = drm_framebuffer_init(dev, &rfb->base, &amdgpu_fb_funcs);
>>       if (ret)
>>           goto err;
> 
-- 
Hamza