[U-Boot] [PATCH 2/2] video: bcm2835: fix various output modes

Stephen Warren swarren at wwwdotorg.org
Wed Oct 23 18:57:53 CEST 2013


On 10/22/2013 09:27 PM, Andre Heider wrote:
> Depending on the firmware's video options [1] the active SDTV or
> HDTV mode can yield a framebuffer with noncontiguous horizontal lines,
> giving a messed up display, for both, u-boot and the loaded kernel.
> 
> To always archive the required contiguousness for the used 16bpp, round
> the framebuffer width down so its aligned to a width of 16.

This doesn't sound like the correct approach. By doing this, either the
SET_PHYSICAL_W_H request will fail since the requested mode doesn't
match the connected display device, or perhaps it'll work, but end up
with a frame-buffer that's a different resolution than the video signal,
so the HW will scale the image slightly, which will reduce quality.

Instead, can't you obtain the buffer width and stride separately, and
then configure the LCD core based on both those values, rather than
assuming they're the same?


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