Hi Am 24.08.23 um 17:22 schrieb Geert Uytterhoeven:
Hi Daniel, On Thu, Aug 24, 2023 at 5:12 PM Daniel Stone <daniel@xxxxxxxxxxxxx> wrote:On Thu, 24 Aug 2023 at 16:09, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:struct drm_client_dev *client = buffer->client; - struct drm_mode_fb_cmd fb_req = { }; - const struct drm_format_info *info; + struct drm_mode_fb_cmd2 fb_req = { }; int ret; - info = drm_format_info(format); - fb_req.bpp = drm_format_info_bpp(info, 0); - fb_req.depth = info->depth; fb_req.width = width; fb_req.height = height; - fb_req.handle = handle; - fb_req.pitch = buffer->pitch; + fb_req.pixel_format = format; + fb_req.handles[0] = handle; + fb_req.pitches[0] = buffer->pitch; - ret = drm_mode_addfb(client->dev, &fb_req, client->file); + ret = drm_mode_addfb2(client->dev, &fb_req, client->file); if (ret) return ret;This should explicitly set the LINEAR modifier (and the modifier flag) if the driver supports modifiers.Thanks for your comment! I have no idea how to do that, and I do not know what the impact would be. All I know is that the current implementation of drm_client_buffer_addfb() does not do that, so changing that in this patch would mean that this would no longer be a trivial conversion.
I agree. That change is too large and invasive for this patchset. Rather add a comment or TODO item.
The correct way for adding the modifier is to extend the drm_client_buffer_addfb() and pass in the information from the caller. That caller is fbdev code. We currently detect the format from (bpp, depth) values and forward the format to _addfb(). [1] Here we'd have to check the driver for a modifier as well and forward it to _addfb()
[1] https://elixir.bootlin.com/linux/v6.5/source/drivers/gpu/drm/drm_fbdev_generic.c#L88
The pair of (bpp, depth) values comes from __drm_fb_helper_find_sizes, [2] which looks through the planes' formats and tries to find something that fits the user's requested color mode. It would have to look for modifiers as well. At some point, I want the helper to return formats directly, but that's still a bit away.
[2] https://elixir.bootlin.com/linux/v6.5/source/drivers/gpu/drm/drm_fb_helper.c#L1504
Best regards Thomas
Gr{oetje,eeting}s,
Geert
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)
Attachment:
OpenPGP_signature
Description: OpenPGP digital signature
