28.04.2021 08:57, Mikko Perttunen пишет:

On 4/28/21 8:51 AM, Dmitry Osipenko wrote:

quoted

23.04.2021 19:32, Thierry Reding пишет:

quoted

Note that there will be no new releases of the bootloader for earlier
devices, so adding support for these new DT bindings will not be
practical. The bootloaders on those devices do pass information about
the active framebuffer via the kernel command-line, so we may want to
add code to create reserved regions in the IOMMU based on that.

Since this change requires a bootloader update anyways, why it's not
possible to fix the bootloader properly, making it to stop all the DMA
activity before jumping into kernel?

That is not desirable, as then we couldn't have seamless
bootloader-kernel boot splash transition.

The seamless transition should be more complicated since it should
require to read out the hardware state in order to convert it into DRM
state + display panel needs to stay ON. It's a bit questionable whether
this is really needed, so far this is not achievable in mainline.

Nevertheless, it will be good to have an early simple-framebuffer, which
I realized only after sending out the message.