6.15-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Zimmermann tzimmermann@suse.de
commit f670b50ef5e4a69bf4d2ec5ac6a9228d93b13a7a upstream.
Use the helper screen_info_video_type() to get the framebuffer type from struct screen_info. Handle supported values in sorted switch statement.
Reading orig_video_isVGA is unreliable. On most systems it is a VIDEO_TYPE_ constant. On some systems with VGA it is simply set to 1 to signal the presence of a VGA output. See vga_probe() for an example. Retrieving the screen_info type with the helper screen_info_video_type() detects these cases and returns the appropriate VIDEO_TYPE_ constant. For VGA, sysfb creates a device named "vga-framebuffer".
The sysfb code has been taken from vga16fb, where it likely didn't work correctly either. With this bugfix applied, vga16fb loads for compatible vga-framebuffer devices.
Fixes: 0db5b61e0dc0 ("fbdev/vga16fb: Create EGA/VGA devices in sysfb code") Cc: Thomas Zimmermann tzimmermann@suse.de Cc: Javier Martinez Canillas javierm@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Tzung-Bi Shih tzungbi@kernel.org Cc: Helge Deller deller@gmx.de Cc: "Uwe Kleine-König" u.kleine-koenig@baylibre.com Cc: Zsolt Kajtar soci@c64.rulez.org Cc: stable@vger.kernel.org # v6.1+ Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Reviewed-by: Tzung-Bi Shih tzungbi@kernel.org Reviewed-by: Javier Martinez Canillas javierm@redhat.com Link: https://lore.kernel.org/r/20250603154838.401882-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firmware/sysfb.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-)
--- a/drivers/firmware/sysfb.c +++ b/drivers/firmware/sysfb.c @@ -143,6 +143,7 @@ static __init int sysfb_init(void) { struct screen_info *si = &screen_info; struct device *parent; + unsigned int type; struct simplefb_platform_data mode; const char *name; bool compatible; @@ -170,17 +171,26 @@ static __init int sysfb_init(void) goto put_device; }
+ type = screen_info_video_type(si); + /* if the FB is incompatible, create a legacy framebuffer device */ - if (si->orig_video_isVGA == VIDEO_TYPE_EFI) - name = "efi-framebuffer"; - else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB) - name = "vesa-framebuffer"; - else if (si->orig_video_isVGA == VIDEO_TYPE_VGAC) - name = "vga-framebuffer"; - else if (si->orig_video_isVGA == VIDEO_TYPE_EGAC) + switch (type) { + case VIDEO_TYPE_EGAC: name = "ega-framebuffer"; - else + break; + case VIDEO_TYPE_VGAC: + name = "vga-framebuffer"; + break; + case VIDEO_TYPE_VLFB: + name = "vesa-framebuffer"; + break; + case VIDEO_TYPE_EFI: + name = "efi-framebuffer"; + break; + default: name = "platform-framebuffer"; + break; + }
pd = platform_device_alloc(name, 0); if (!pd) {