> From: Olaf Hering > Sent: Thursday, February 21, 2013 10:53 AM > To: Haiyang Zhang > Cc: florianschandi...@gmx.de; linux-fb...@vger.kernel.org; KY Srinivasan; > jasow...@redhat.com; email@example.com; > de...@linuxdriverproject.org > Subject: Re: [PATCH RFC] video: Add Hyper-V Synthetic Video Frame Buffer > Driver > > On Tue, Feb 19, Haiyang Zhang wrote: > > > In my test, the vesafb doesn't automatically give up the emulated video > > device, > > unless I add the DMI based mechanism to let it exit on Hyper-V. > > From reading the code, it seems to do that via > do_remove_conflicting_framebuffers(). hypervfb does not set apertures > etc, so that function is a noop.
We are currently allocating a new framebuffer for hyperv_fb, which is different from the framebuffer for the emulated video. So this cannot be detected by do_remove_conflicting_framebuffers() based on apertures_overlap(). > My point is that with this new driver distro kernel will have no console > output until hypervfb is loaded. On native hardware there is at least > vesafb which can display something until initrd is running. So if the > hypervisor allows that hypervfb can shutdown the emulated vesa hardware > then it should do that. Since the generic vga driver starts to work early in the boot process, the console messages are still displayed without vesafb. Actually, I didn't see any console messages missing when comparing it to the original VM before my patch. Thanks, - Haiyang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/