bug#60010: [version 1.4.0] AMD screen stays black; modprobe fails

["pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de>]

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Hello Ludo, sorry to say I attempted your modprobe patch that uses
(parameterize ((default-environment-variables …

No good.  Screen is black.  Same [ modprobe ] failure in dmesg on QEMU
and on real AMD hardware.

There are workarounds by surrounding modprobe within strace or
alternatively using kernel-module-loader-service (attached; but again,
without the file-exists? check, this would cause new issues on some
machines that dont need uvesafb).

A stupid

diff --git a/gnu/system/install.scm b/gnu/system/install.scm
index f6f1923121..a99cf09e31 100644
--- a/gnu/system/install.scm
+++ b/gnu/system/install.scm
@@ -289,6 +289,7 @@ (define (uvesafb-shepherd-service _)
          (provision '(maybe-uvesafb))
          (requirement '(file-systems))
          (start #~(lambda ()
+                   (sleep 1)
                     (or (file-exists? "/dev/fb0")
                         (invoke #+(file-append kmod "/bin/modprobe")
                                 "uvesafb"


fails though.

All bad…

Regards,
Florian

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diff --git a/gnu/system/install.scm b/gnu/sysdiff --git a/gnu/system/install.scm b/gnu/system/install.scm
index f6f1923121..2a1f401536 100644
--- a/gnu/system/install.scm
+++ b/gnu/system/install.scm
@@ -40,6 +40,7 @@ (define-module (gnu system install)
   #:use-module (gnu system locale)
   #:use-module (gnu services avahi)
   #:use-module (gnu services dbus)
+  #:use-module (gnu services linux)
   #:use-module (gnu services networking)
   #:use-module (gnu services shepherd)
   #:use-module (gnu services ssh)
@@ -283,29 +284,22 @@ (define %nscd-minimal-caches
 ;; These define a service to load the uvesafb kernel module with the
 ;; appropriate options.  The GUI installer needs it when the machine does not
 ;; support Kernel Mode Setting.  Otherwise kmscon is missing /dev/fb0.
-(define (uvesafb-shepherd-service _)
-  (list (shepherd-service
-         (documentation "Load the uvesafb kernel module if needed.")
-         (provision '(maybe-uvesafb))
-         (requirement '(file-systems))
-         (start #~(lambda ()
-                    (or (file-exists? "/dev/fb0")
-                        (invoke #+(file-append kmod "/bin/modprobe")
-                                "uvesafb"
-                                (string-append "v86d=" #$v86d "/sbin/v86d")
-                                "mode_option=1024x768"))))
-         (respawn? #f)
-         (one-shot? #t))))
-
-(define uvesafb-service-type
-  (service-type
-   (name 'uvesafb)
-   (extensions
-    (list (service-extension shepherd-root-service-type
-                             uvesafb-shepherd-service)))
-   (description
-    "Load the @code{uvesafb} kernel module with the right options.")
-   (default-value #t)))
+(define uvesafb-config
+  (computed-file "uvesafb.conf"
+                 #~(with-output-to-file #$output
+                     (lambda ()
+                       (display
+                        (string-append "options uvesafb"
+                                      " " "v86d=" #$v86d "/sbin/v86d"
+                                       " " "mode_option=1024x768"))))))
+
+(define uvesafb-services
+  (list (service kernel-module-loader-service-type
+                 '("uvesafb"))
+       (simple-service 'uvesafb-config etc-service-type
+                                             (list `("modprobe.d/uvesafb.conf"
+                                                     ,uvesafb-config)))))
+       
 
 (define* (%installation-services #:key (system (or (and=>
                                                     (%current-target-system)
@@ -450,8 +444,7 @@ (define bare-bones-os
      ;; installer.  Some may also need a kernel parameter like nomodeset
      ;; or vga=793, but we leave that for the user to specify in GRUB.
      `(,@(if (supported-package? v86d system)
-             (list (service uvesafb-service-type))
-             '())))))
+             uvesafb-services)))))
 
 (define %issue
   ;; Greeting.