Re: [PATCH] drm/simpledrm: Only advertise formats that are supported

From: Thomas Zimmermann
Date: Fri Oct 28 2022 - 07:11:47 EST


Hi

Am 28.10.22 um 12:04 schrieb Ville Syrjälä:
On Thu, Oct 27, 2022 at 01:08:24PM +0200, Thomas Zimmermann wrote:
I trust you when you say that <native>->XRGB8888 is not enough. But
although I've read your replies, I still don't understand why this
switch is necessary.

Why don't we call drm_fb_build_fourcc_list() with the native
format/formats and let it append a number of formats, such as adding
XRGB888, adding ARGB8888 if necessary, adding ARGB2101010 if necessary.
Each with a elaborate comment why and which userspace needs the format. (?)

Are you saying there is some real userspace that breaks without
the alpha formats? That would already be broken on many devices.

We should scrap them all IMHO, unless the hardware really supports them. See the other discussion on this patch's v2 as well.

Best regards
Thomas



--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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