> -----Original Message----- > From: David Herrmann [mailto:dh.herrmann@xxxxxxxxx] > Sent: Friday, August 16, 2013 3:11 PM > To: Haiyang Zhang > Cc: linux-fbdev@xxxxxxxxxxxxxxx; driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; > Tomi Valkeinen; Jean-Christophe Plagniol-Villard; akpm@linux- > foundation.org; KY Srinivasan > Subject: Re: conflict of hyperv_fb and the generic video driver? > > Hi > > (hint: your mail header seems to drop Reference-to/Reply-to headers > and breaks thread-info) > > On Fri, Aug 16, 2013 at 8:45 PM, Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> > wrote: > > > > > >> -----Original Message----- > >> From: David Herrmann [mailto:dh.herrmann@xxxxxxxxx] > >> Sent: Friday, August 16, 2013 9:46 AM > >> To: Haiyang Zhang > >> Cc: linux-fbdev@xxxxxxxxxxxxxxx; driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; > >> Tomi Valkeinen; Jean-Christophe Plagniol-Villard; akpm@linux- > >> foundation.org; KY Srinivasan > >> Subject: Re: source code file for the generic vga driver? > >> > >> Hi > >> > >> On Mon, Aug 5, 2013 at 9:12 PM, Haiyang Zhang > <haiyangz@xxxxxxxxxxxxx> > >> wrote: > >> > Hi folks, > >> > > >> > I'm working on an issue of HyperV synthetic frame buffer driver, which > >> > seems to have a conflict with the generic vga driver (not the vesa > >> > driver). I hope to read and trace into the source code for the generic vga > >> driver... > >> > > >> > Can anyone point me to the source code file for the generic vga driver in > >> the kernel tree? > >> > >> Everything lives in ./drivers/video/. The drivers you're probably interested > in > >> are "vesafb.c" or "vga16fb.c". There is also the "vgacon" driver > >> in ./drivers/video/console/vgacon.c. I am not sure which one you are > talking > >> about. > >> > >> You might also want to have a look at the x86 sysfb infrastructure which > isn't > >> merged, yet: > >> http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/log/?h=x86/fb > >> It provides proper platform-devices so drivers no longer conflict on the > >> vga/vesa/efi.. framebuffer resources. It's x86 only as all the relevant > drivers > >> only work on x86. > >> > >> If you give some more information on what you are trying to do, I can > point > >> you to the relevant resources. My guess is that you want to have a look at > >> remove_conflicting_framebuffers() in ./drivers/video/fbmem.c. > > > > Thank you for the detailed reply! > > > > I'm looking at a problem of Hyper-V synthetic fb driver (hyperv_fb) which > seems > > to have conflict with some kind of generic video driver. I'm not sure which > driver > > is this. > > > > On Suse, the vesafb is removed automatically by > remove_conflicting_framebuffers() > > when hyperv_fb is loaded. We don't have any problem here. > > > > On some other Distros, like RHEL, CentOS, Ubuntu, the generic driver > seems not > > to be vesafb -- I can't see any /dev/fb* there. And, the generic video driver > seems not be > > removed when hyperv_fb is loaded. This generic video driver is not vesafb > or vga16fb or > > vgacon, because it supports x-window GUI, and it's still here after I un- > configured vesafb > > and vga16fb. > > > > Could point out what is the generic video driver used by RHEL, Ubuntu by > default? And, > > how to let it exit automatically when our FB driver (hyperv_fb) is loaded? > > I have no idea what RHEL or Ubuntu use, sorry. But your description > sounds odd. The kernel has 3 different places that could use VGA > resources: > - fbdev drivers (/dev/fbX or /sys/class/graphics) > - DRM drivers (/dev/dri/cardX or /sys/class/drm) > - vgacon > Could you check whether these directories are empty? > (/sys/class/graphics/ and /sys/class/drm/ on a running machine) > > If these are empty, this doesn't look like a kernel thing. Are you > sure it's a kernel driver that accesses your VGA resources? The > xserver used to have some pretty huge vga/vesa/.. user-space drivers. > > Could you tell me whether the linux-console actually works? That is, > do you get some console output if xserver is not running? To find out the default driver, I manually removed my hyperv_fb driver. The vesafb is unconfigured: # CONFIG_FB_BOOT_VESA_SUPPORT is not set # CONFIG_FB_UVESA is not set # CONFIG_FB_VESA is not set But I saw VESA VBE in the x log. Seems it's the default driver: "/var/log/Xorg.0.log": [ 12.340] (II) VESA(0): Primary V_BIOS segment is: 0xc000 [ 12.341] (II) VESA(0): VESA BIOS detected [ 12.341] (II) VESA(0): VESA VBE Version 2.0 [ 12.341] (II) VESA(0): VESA VBE Total Mem: 4096 kB [ 12.341] (II) VESA(0): VESA VBE OEM: IBM SVGA BIOS, (C) 1993 International Business Machines [ 12.341] (II) VESA(0): VESA VBE OEM Software Rev: 0.0 [ 12.365] (II) VESA(0): Creating default Display subsection in Screen section "Default Screen Section" for depth/fbbpp 24/32 [ 12.365] (==) VESA(0): Depth 24, (--) framebuffer bpp 32 [ 12.365] (==) VESA(0): RGB weight 888 [ 12.365] (==) VESA(0): Default visual is TrueColor [ 12.365] (==) VESA(0): Using gamma correction (1.0, 1.0, 1.0) There is no /dev/fb*, /dev/dri/, /sys/class/drm I see /sys/class/graphics/fbcon is here. But console output is not working. Seems that the VESA VBE is causing conflict with my driver... Is there any way to disable VESA VBE driver? Thanks, - Haiyang _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
