On Wed, 24 Apr 2024, Andy Pont <andy.pont@xxxxxxxxxxx> wrote: > Hello, > > I’m working on the coreboot port for a laptop which uses the N200 > (AlderLake-N). The built in LCD and HDMI port are working correctly but > I am having problems with driving an external display over USB. > > The Linux kernel (6.5.0-27-generic in Ubuntu 23.10) gives a message that > says: > > i915 0000:00:02.0: [drm] *ERROR* Timeout waiting for DDI BUF D to get > active > > The timeout occurs in hsw_wait_for_power_well_enable(). I have put the > full dmesg output of the drm_WARN_ON() messages on Pastebin[1]. > > I’m guessing something in the FSP isn’t being correctly configured but I > don’t know whether it is graphics, USB, or power related. > > Thanks in advance for any advice on where to look. Does it work all right with the stock UEFI boot, and you're only seeing issues with coreboot? Is /sys/kernel/debug/dri/0/i915_vbt the same for both? Might be easier to file a bug as described at [1], and attach full dmesg with debugs enabled. BR, Jani. [1] https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html > > -Andy. > > 1. https://pastebin.com/p3JTYpTC > -- Jani Nikula, Intel
