Hello,

On Fri, Feb 18, 2022 at 10:57:33AM +0100, Thomas Zimmermann wrote:

Hi Michal

Am 18.02.22 um 10:33 schrieb Michal Suchanek:

quoted

Since switch to simpledrm VESA graphic modes are no longer available
with legacy BIOS.

The x86 realmode boot code enables the VESA graphic modes when option
FB_BOOT_VESA_SUPPORT is enabled.

To enable use of VESA modes with simpledrm in legacy BIOS boot mode drop
dependency of BOOT_VESA_SUPPORT on FB, also drop the FB_ prefix, and
select the option when simpledrm is built-in on x86.

Thanks for sending the patch.

I tested simpledrm on a VESA-based systems and it work. Do you have a

In EFI or legacy mode?

concrete example of a mode that doesn't work any longer?

As per discussion in
https://bugzilla.opensuse.org/show_bug.cgi?id=1193250 vga=791 does not.

Also it is clear examinig the realmode code that this option is needed
to enable graphic mode selection.

I don't have a system with legacy BIOS at hand but from user testing
this improves the situation - kernel does not reeject the videomode
argument, and simpledrm is initialized during boot.

Thanks

Michal

quoted

Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Signed-off-by: Michal Suchanek <redacted>
---
  arch/x86/boot/video-vesa.c   | 4 ++--
  drivers/gpu/drm/tiny/Kconfig | 1 +
  drivers/video/fbdev/Kconfig  | 9 ++++-----
  3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/boot/video-vesa.c b/arch/x86/boot/video-vesa.c
index 7e185977a984..c2c6d35e3a43 100644
--- a/arch/x86/boot/video-vesa.c
+++ b/arch/x86/boot/video-vesa.c

@@ -83,7 +83,7 @@ static int vesa_probe(void)
  			   (vminfo.memory_layout == 4 ||
  			    vminfo.memory_layout == 6) &&
  			   vminfo.memory_planes == 1) {
-#ifdef CONFIG_FB_BOOT_VESA_SUPPORT
+#ifdef CONFIG_BOOT_VESA_SUPPORT
  			/* Graphics mode, color, linear frame buffer
  			   supported.  Only register the mode if
  			   if framebuffer is configured, however,

@@ -121,7 +121,7 @@ static int vesa_set_mode(struct mode_info *mode)
  	if ((vminfo.mode_attr & 0x15) == 0x05) {
  		/* It's a supported text mode */
  		is_graphic = 0;
-#ifdef CONFIG_FB_BOOT_VESA_SUPPORT
+#ifdef CONFIG_BOOT_VESA_SUPPORT
  	} else if ((vminfo.mode_attr & 0x99) == 0x99) {
  		/* It's a graphics mode with linear frame buffer */
  		is_graphic = 1;

diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig
index 712e0004e96e..1bc30c64ed15 100644
--- a/drivers/gpu/drm/tiny/Kconfig
+++ b/drivers/gpu/drm/tiny/Kconfig

@@ -54,6 +54,7 @@ config DRM_GM12U320
  config DRM_SIMPLEDRM
  	tristate "Simple framebuffer driver"
  	depends on DRM && MMU
+	select BOOT_VESA_SUPPORT if X86 && DRM_SIMPLEDRM = y

We shouldn't select this option in drivers IMHO. Simple-framebuffer devices
with VESA are enabled with [1] and that should also select the
BOOT_VESA_SUPPORT.

Sounds ok to select from there, it should also cover simplefb then.

Thanks

Michal