Source: linux Version: 4.9~rc5-1~exp1 Followup-For: Bug #822575 Dear Maintainer, I have the same problem with cirrusfb: After that last message the screen does not update anymore (but I can login through ssh). After lots of research I things the problem is related to CONFIG_X86_SYSFB being enabled in Debian by default: $ git rev-parse HEAD # git://anonscm.debian.org/kernel/linux.git 6c0c9bcf78dfc886907d006b8cb6c2ea0f075a62 $ git grep -n -F -e CONFIG_X86_SYSFB -e CONFIG_FB_SIMPLE config/armhf/config:1187:CONFIG_FB_SIMPLE=y config/kernelarch-x86/config:73:CONFIG_X86_SYSFB=y config/kernelarch-x86/config:1776:CONFIG_FB_SIMPLE=y By default the video RAM is claimed by the boot framebbuffer: > # cat /proc/fb > 0 simple > # grep 80000000 /proc/iomem > 80000000-febfffff : PCI Bus 0000:00 > 80000000-81ffffff : 0000:00:02.0 > 80000000-801d4fff : BOOTFB When cirrusdrmfb loads, it disabled the bootfb and tries to claim that region. As it is still held by bootfb, this failes: > # modprobe cirrus > # dmesg > [ 263.171744] checking generic (80000000 1d5000) vs hw (80000000 2000000) > [ 263.171753] fb: switching to cirrusdrmfb from simple > [ 263.171838] Console: switching to colour dummy device 80x25 > [ 263.177052] [drm:cirrus_device_init [cirrus]] *ERROR* can't reserve VRAM > [ 263.177066] cirrus 0000:00:02.0: Fatal error during GPU init: -6 > [ 263.177072] Trying to free nonexistent resource <0000000082029000-0000000082029fff> > [ 263.177080] Trying to free nonexistent resource <0000000080000000-0000000081ffffff> /proc/fb is empty afterwards, as bootfb remains disabled. My solution was to remove cirrus.ko and cirrusfb.ko from /lib/modules/`uname -r`/kernel/ and to re-build the initramfs. That prevented cirrus from being loaded, leaving the simple-frame-buffer intact. Loading the module by hand breaks the console again. I found that SUSE bug <https://bugzilla.novell.com/show_bug.cgi?id=855821>, where Takashi Iwai finally disabled those options for OpenSUSE. Ubuntu disabled the Cirrus drm driver first, <https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1038055> but later changed to only disable X86_SYSFB. So probably it's best to disable X86_SYSFB: > config X86_SYSFB > bool "Mark VGA/VBE/EFI FB as generic system framebuffer" > help > Firmwares often provide initial graphics framebuffers so the BIOS, > bootloader or kernel can show basic video-output during boot for > user-guidance and debugging. Historically, x86 used the VESA BIOS > Extensions and EFI-framebuffers for this, which are mostly limited > to x86. > This option, if enabled, marks VGA/VBE/EFI framebuffers as generic > framebuffers so the new generic system-framebuffer drivers can be > used on x86. If the framebuffer is not compatible with the generic > modes, it is adverticed as fallback platform framebuffer so legacy > drivers like efifb, vesafb and uvesafb can pick it up. > If this option is not selected, all system framebuffers are always > marked as fallback platform framebuffers as usual. > > Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will > not be able to pick up generic system framebuffers if this option > is selected. You are highly encouraged to enable simplefb as > replacement if you select this option. simplefb can correctly deal > with generic system framebuffers. But you should still keep vesafb > and others enabled as fallback if a system framebuffer is > incompatible with simplefb. > > If unsure, say Y. If you read <https://patchwork.kernel.org/patch/3380911/> there was a patched proposed to change it to 'N' and/or to depend on FB_SIMPLE, but that patch never made it into linux. Nor did <https://patchwork.kernel.org/patch/3368351/> or <https://patchwork.kernel.org/patch/3528991/>. I tried to contact David Herrmann himself, but never got a reply. So I think Debian should disable X86_SYSFB for now, too. Thank you for your work and help Philipp "also a Debian maintainer" Hahn -- System Information: Debian Release: 8.6 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable'), (90, 'testing') Architecture: amd64 (x86_64) Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores) Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
