ACK: [SRU][R/S][PATCH 0/1] Fix incorrect boot_display reporting on multi-GPU systems

[Tim Whisonant]

On Fri, Jul 17, 2026 at 05:10:44PM +0800, Aaron Ma via kernel-team wrote:
> BugLink: https://bugs.launchpad.net/bugs/2161036
> 
> SRU Justification:
> 
> [Impact]
> On multi-GPU systems, a VGA-compatible device that is not driving the display
> can incorrectly be reported as the primary graphics device through the
> boot_display sysfs attribute.
> 
> [Fix]
> Apply upstream commit 596b3678326d3d1aed7c19423b6746f1ce09688a
> ("x86/video: Only fall back to vga_default_device() without screen info").
> 
> When framebuffer screen information is valid, use it exclusively to identify
> the primary device. Fall back to vga_default_device() only when no framebuffer
> has been set up.
> 
> [Test Plan]
> Boot a multi-GPU system and verify that boot_display identifies only the GPU
> backing the framebuffer. Verify fallback behavior when no framebuffer has
> been initialized.
> 
> [Where problems could occur]
> The change is limited to primary display-device detection in
> arch/x86/video/video-common.c. The main risk is incorrect identification of the
> primary GPU on systems with unusual or incomplete framebuffer information.
> 
> Mario Limonciello (1):
>   x86/video: Only fall back to vga_default_device() without screen info
> 
>  arch/x86/video/video-common.c | 23 ++++++++++++++---------
>  1 file changed, 14 insertions(+), 9 deletions(-)
> 
> -- 
> 2.43.0
> 

Acked-by: Tim Whisonant <tim.whisonant at canonical.com>