[PATCH] drm/xe: Support 'nomodeset' kernel command-line option

[Thomas Zimmermann <tzimmermann@suse.de>]

Setting 'nomodeset' on the kernel command line disables all graphics
drivers with modesetting capabilities; leaving only firmware drivers,
such as simpledrm or efifb.

Most DRM drivers automatically support 'nomodeset' via DRM's module
helper macros. In xe, which uses regular module_init(), manually call
drm_firmware_drivers_only() to test for 'nomodeset'. Do not register
the driver if set.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/xe/xe_module.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
index 923460119cec..60fb7dd26903 100644
--- a/drivers/gpu/drm/xe/xe_module.c
+++ b/drivers/gpu/drm/xe/xe_module.c
@@ -8,6 +8,8 @@
 #include <linux/init.h>
 #include <linux/module.h>
 
+#include <drm/drm_module.h>
+
 #include "xe_drv.h"
 #include "xe_hw_fence.h"
 #include "xe_pci.h"
@@ -92,6 +94,9 @@ static int __init xe_init(void)
 {
 	int err, i;
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	for (i = 0; i < ARRAY_SIZE(init_funcs); i++) {
 		err = init_funcs[i].init();
 		if (err) {
-- 
2.46.0