Re: [PATCH v2 0/7] vga_switcheroo, drm: Push fbcon handling into DRM clients

[Thomas Zimmermann <tzimmermann@suse.de>]

Hi

Am 18.07.26 um 21:08 schrieb Helge Deller:
> Hi Thomas,
>
> On 7/9/26 11:15, Thomas Zimmermann wrote:
>> Vga_switcheroo currently invokes fb_switch_outputs() to inform fbcon
>> about switching of the physical outputs among framebuffer devices. But
>> new DRM clients to not use fbdev/fbcon and might require their own
>> vga_switcheroo support. Let's strictly separate them from each other.
>>
>> Remove fbdev/fbcon from vga_switcheroo. Introduce a pre_switch callback
>> for vga_switcheroo clients to do the fbcon update. Allows for removing
>> all direct interactions between vga_switcheroo and fbdev/fbcon.
>>
>> There are only four drivers that support vga_switcheroo: amdgpu,
>> radeon, i915 and nouveau. Update each of them with the new callback.
>> When vga_switcheroo now invokes pre_switch, each DRM driver forwards
>> to aquire_outputs and lets the DRM clients handle the new outputs.
>>
>> At the same time, push the fbcon update into DRM's client for fbdev
>> emulation. Do this with the new DRM client callback acquire_outputs,
>> so that other clients can have their own handling of vga_switcheroo.
>>
>> Also replace the existing reprobe hook with post_switch for symetry.
>> For nouveau, this is merely a rename of the helper function. The other
>> drivers dor not implement reprobe.
>>
>> Tested with radeon on a notebook with Radeon HD 4225 and HD 5430.
>>
>> v2:
>> - implement all of pre_switch in a single commit to avoid possible
>>    deadlock in intermediate state (Sashiko)
>> - fix erroneous docs (Sashiko)
>>
>> Thomas Zimmermann (7):
>>    drm/edid: Include <linux/fb.h>
>>    drm/client: Add acquire_outputs callback; implement for fbdev
>>      emulation
>>    vga_switcheroo: Add pre_switch callback to client ops
>>    vga_switcheroo: Add post_switch callback to client ops
>>    drm: Implement struct vga_switcheroo_client_ops.pre_switch
>>    drm: Implement vga_switcheroo_client_ops.post_switch
>>    vga-switcheroo: Remove unused interfaces
>>
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  9 ++++-
>>   drivers/gpu/drm/clients/drm_fbdev_client.c | 23 ++++++++----
>>   drivers/gpu/drm/drm_client_event.c         | 18 ++++++++++
>>   drivers/gpu/drm/drm_edid.c                 |  1 +
>>   drivers/gpu/drm/i915/i915_switcheroo.c     | 11 +++++-
>>   drivers/gpu/drm/nouveau/nouveau_vga.c      | 28 +++++++++------
>>   drivers/gpu/drm/radeon/radeon_device.c     |  9 ++++-
>>   drivers/gpu/vga/vga_switcheroo.c           | 41 +++++-----------------
>>   drivers/video/fbdev/core/fbcon.c           |  8 -----
>>   include/drm/drm_client.h                   | 14 ++++++++
>>   include/drm/drm_client_event.h             |  3 ++
>>   include/linux/vga_switcheroo.h             | 29 ++++++++-------
>>   12 files changed, 121 insertions(+), 73 deletions(-)
> You may add a
> Acked-by: Helge Deller <deller@gmx.de>
> to the series.

Thank you so much.

>
> Just in case you want me to take the series through the fbdev git tree,
> please let me know.

The series is supposed to go though DRM trees. I'm still waiting for 
reviews from the rsp devs.

Best regards
Thomas


>
> Helge

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)