| Message ID | 20250603154838.401882-1-tzimmermann@suse.de |
|---|---|
| State | New |
| Headers | show |
| Series | sysfb: Fix screen_info type check for VGA | expand |
Thomas Zimmermann <tzimmermann@suse.de> writes: > 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. > Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c index 7c5c03f274b9..889e5b05c739 100644 --- 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) {
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> --- drivers/firmware/sysfb.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-)