From: Mario Limonciello (AMD) <superm1@kernel.org>
Date: Mon, 11 Aug 2025 16:26:05 +0000 (-0500)
Subject: fbcon: Use screen info to find primary device
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ad90860bd10ee3ed387077aed88828b139339976;p=users%2Fhch%2Fmisc.git

fbcon: Use screen info to find primary device

On systems with non VGA GPUs fbcon can't find the primary GPU because
video_is_primary_device() only checks the VGA arbiter.

Add a screen info check to video_is_primary_device() so that callers
can get accurate data on such systems.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20250811162606.587759-4-superm1@kernel.org
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---

diff --git a/arch/x86/video/video-common.c b/arch/x86/video/video-common.c
index 81fc97a2a837..e0aeee99bc99 100644
--- a/arch/x86/video/video-common.c
+++ b/arch/x86/video/video-common.c
@@ -9,6 +9,7 @@
 
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/screen_info.h>
 #include <linux/vgaarb.h>
 
 #include <asm/video.h>
@@ -27,6 +28,11 @@ EXPORT_SYMBOL(pgprot_framebuffer);
 
 bool video_is_primary_device(struct device *dev)
 {
+#ifdef CONFIG_SCREEN_INFO
+	struct screen_info *si = &screen_info;
+	struct resource res[SCREEN_INFO_MAX_RESOURCES];
+	ssize_t i, numres;
+#endif
 	struct pci_dev *pdev;
 
 	if (!dev_is_pci(dev))
@@ -34,7 +40,24 @@ bool video_is_primary_device(struct device *dev)
 
 	pdev = to_pci_dev(dev);
 
-	return (pdev == vga_default_device());
+	if (!pci_is_display(pdev))
+		return false;
+
+	if (pdev == vga_default_device())
+		return true;
+
+#ifdef CONFIG_SCREEN_INFO
+	numres = screen_info_resources(si, res, ARRAY_SIZE(res));
+	for (i = 0; i < numres; ++i) {
+		if (!(res[i].flags & IORESOURCE_MEM))
+			continue;
+
+		if (pci_find_resource(pdev, &res[i]))
+			return true;
+	}
+#endif
+
+	return false;
 }
 EXPORT_SYMBOL(video_is_primary_device);