Wrong BMP colours on i.MX after updating 2018.11 => 2020.10

[Fabio Estevam]

Hi Martin,

Thanks for the report. Adding Anatolij.

On Tue, Jan 12, 2021 at 1:11 PM Fuzzey, Martin
<martin.fuzzey at flowbird.group> wrote:
>
> Hi all,
>
> After updating from u-boot 2018.11 to 2020.10 on an i.MX6 based board
> I notice the colours when displaying bitmaps are wrong.
> The reason is that, in both cases the framebuffer format (not
> necessarily the physical output format) is hardcoded as RGB565 in the
> IPU driver but the
> bmp command is now assuming RGB55
>
> This is because, in 2018.10 (before DM_VIDEO support for the i.MX
> display was available) video_display_bitmap() in
> drivers/video/cfb_console.c
> was being used which supports both RGB565 and RGB555 depending on the
> "gdfIndex" in a global graphics device structure.
>
> Now with DM_VIDEO video_bmp_display() in drivers/video/video_bmp.c is
> used instead and that always assumes RGB555 when
> displaying a 24 bit BMP on a  16 bit framebuffer.
>
> Of course this is easy to hack around but what is the correct solution?
>
> Maybe we should add a format field to struct video_priv that could be
> initialised by the driver like xsize, ysize and bpix already are?
>
> Regards,
>
> Martin