r<#secure method=pgpmime mode=sign> Stephen Warren swarren@wwwdotorg.org writes:
On 08/12/2015 06:56 PM, Eric Anholt wrote:
This is the start of a full VC4 driver. Right now this just supports configuring the display using a pre-existing video mode (because changing the pixel clock isn't available yet, and doesn't work when it is). However, this is enough for fbcon and bringing up X using xf86-video-modesetting.
diff --git a/drivers/gpu/drm/vc4/Kconfig b/drivers/gpu/drm/vc4/Kconfig
+config DRM_VC4
- tristate "Broadcom VC4 Graphics"
- help
Choose this option if you have a system that has a BroadcomVC4 GPU, such as the Raspberry Pi or other BCM2708/BCM2835.This driver requires that "avoid_warnings=2" be present inthe config.txt for the firmware, to keep it from smashingour display setup.The need for "avoid_warnings=2" seems like it will trip people up. I don't think it's in any config.txt I've seen. Can you expand more on that?
The warnings thing is the firmware watching for undervoltage and then it calls into dispmanx to overlay a little rainbow box on the screen. This of course interferes with our display setup.
I think we'll be able to wire up notifications to Linux for undervoltage, at which point we can do something useful with that information, ourselves.