From 72899f8d89744c8014ff74ea6496923684e8c2b5 Mon Sep 17 00:00:00 2001
From: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Date: Sat, 4 Jan 2025 01:03:29 +0300
Subject: [PATCH] Handle framebuffer_coreboot driver built as a module

The driver for coreboot firmware-initialized framebuffer can be built as
a module. Debian kernels so far have it as built-in because they would
not be probed automatically when built as a module. This is fixed now,
likely with a patchset included in v6.9-rc1, so we might encounter it as
a module either in Debian or with custom-built kernels.

For MODULES=dep, check for the coreboot framebuffer in a different block
from other platform drivers, and include the framebuffer_coreboot module
if we find the device. For MODULES=most, add driver to the framebuffer
modules list. Explicitly try to probe the module for break=top because
it would not automatically probe there otherwise. Since it requires a
driver for the "simple-framebuffer" device, add simpledrm and simplefb
as its hidden dependencies.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
---
 hook-functions    | 16 +++++++++++++---
 scripts/functions |  2 +-
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/hook-functions b/hook-functions
index 9927155..893ee16 100644
--- a/hook-functions
+++ b/hook-functions
@@ -639,14 +639,20 @@ dep_add_modules()
 	for device in /sys/bus/platform/drivers/efi-framebuffer/* \
 	              /sys/bus/platform/drivers/platform-framebuffer/* \
 	              /sys/bus/platform/drivers/simple-framebuffer/* \
-	              /sys/bus/platform/drivers/vesa-framebuffer/* \
-	              /sys/bus/coreboot/drivers/framebuffer/*; do
+	              /sys/bus/platform/drivers/vesa-framebuffer/*; do
 		if [ -d "$device" ] && [ "$(basename "$device")" != "module" ]; then
 			walk_graphics=no
 			break
 		fi
 	done
 
+	for device in /sys/bus/coreboot/drivers/framebuffer/*; do
+		if [ -d "$device" ] && [ "$(basename "$device")" != "module" ]; then
+			modules="$modules framebuffer_coreboot"
+			walk_graphics=no
+		fi
+	done
+
 	# It's possible that a generic framebuffer device works, but is taken
 	# over by a more capable driver and no longer available in /sys. We
 	# have no reliable consistent way to detect that, so apply heuristics.
@@ -850,7 +856,7 @@ auto_add_modules()
 			modules="$modules =drivers/usb/storage"
 		;;
 		fb)
-			modules="$modules simpledrm simplefb"
+			modules="$modules simpledrm simplefb framebuffer_coreboot"
 			# For machines that don't have a generic framebuffer device.
 			modules="$modules rockchipdrm pwm-cros-ec pwm_bl pwm-rockchip panel-simple"
 			modules="$modules analogix-anx6345 pwm-sun4i sun4i-drm sun8i-mixer panel-edp"
@@ -942,6 +948,10 @@ hidden_dep_add_modules()
 				# DP devices which don't have devlinks
 				echo pmic_glink_altmode gpio_sbu_mux qrtr
 				;;
+			framebuffer_coreboot)
+				# Either one, we don't know which is a module
+				echo simpledrm simplefb
+				;;
 			esac
 		done
 		)
diff --git a/scripts/functions b/scripts/functions
index 7e9dd7a..1e8b26f 100644
--- a/scripts/functions
+++ b/scripts/functions
@@ -103,7 +103,7 @@ maybe_break()
 			/sbin/modprobe ${opts} -a i8042 atkbd ehci-pci ehci-orion \
 				 ehci-hcd ohci-hcd ohci-pci uhci-hcd usbhid xhci \
 				 xhci-pci xhci-hcd
-			/sbin/modprobe ${opts} -a simpledrm simplefb
+			/sbin/modprobe ${opts} -a simpledrm simplefb framebuffer_coreboot
 			sleep 2
 			for modalias in /sys/bus/hid/devices/*/modalias; do
 				if [ -f "${modalias}" ]; then