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From: "Mario Limonciello (AMD)" <superm1@kernel.org>
To: mario.limonciello@amd.com, bhelgaas@google.com,
	superm1@kernel.org, tzimmermann@suse.de
Cc: Eric Biggers <ebiggers@kernel.org>, linux-pci@vger.kernel.org
Subject: [PATCH v2] PCI/VGA: Select SCREEN_INFO
Date: Mon, 13 Oct 2025 10:44:23 -0500	[thread overview]
Message-ID: <20251013154441.1000875-1-superm1@kernel.org> (raw)

commit 337bf13aa9dda ("PCI/VGA: Replace vga_is_firmware_default() with
a screen info check") introduced an implicit dependency upon SCREEN_INFO
by removing the open coded implementation.

If a user didn't have CONFIG_SCREEN_INFO set vga_is_firmware_default()
would now return false.  Add a select for SCREEN_INFO to ensure that the
VGA arbiter works as intended. Also drop the now dead code.

Reported-by: Eric Biggers <ebiggers@kernel.org>
Closes: https://lore.kernel.org/linux-pci/20251012182302.GA3412@sol/
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 337bf13aa9dda ("PCI/VGA: Replace vga_is_firmware_default() with a screen info check")
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
v2:
 * drop dead code (Ilpo)
---
 drivers/pci/Kconfig  | 1 +
 drivers/pci/vgaarb.c | 8 +-------
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 7065a8e5f9b14..c35fed47addd5 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -306,6 +306,7 @@ config VGA_ARB
 	bool "VGA Arbitration" if EXPERT
 	default y
 	depends on (PCI && !S390)
+	select SCREEN_INFO
 	help
 	  Some "legacy" VGA devices implemented on PCI typically have the same
 	  hard-decoded addresses as they did on ISA. When multiple PCI devices
diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index b58f94ee48916..8c8c420ff5b55 100644
--- a/drivers/pci/vgaarb.c
+++ b/drivers/pci/vgaarb.c
@@ -556,13 +556,7 @@ EXPORT_SYMBOL(vga_put);
 
 static bool vga_is_firmware_default(struct pci_dev *pdev)
 {
-#ifdef CONFIG_SCREEN_INFO
-	struct screen_info *si = &screen_info;
-
-	return pdev == screen_info_pci_dev(si);
-#else
-	return false;
-#endif
+	return pdev == screen_info_pci_dev(&screen_info);
 }
 
 static bool vga_arb_integrated_gpu(struct device *dev)
-- 
2.43.0


             reply	other threads:[~2025-10-13 15:44 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-13 15:44 Mario Limonciello (AMD) [this message]
2025-10-13 16:10 ` [PATCH v2] PCI/VGA: Select SCREEN_INFO Thomas Zimmermann
2025-10-13 16:39 ` Ilpo Järvinen
2025-10-13 17:55 ` Bjorn Helgaas
2025-10-13 20:47   ` Bjorn Helgaas
2025-10-13 20:48     ` Mario Limonciello

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