Date: Fri, 26 Nov 2021 17:16:17 +0100 From: Emmanuel Vadot <manu@bidouilliste.com> To: Stefan Blachmann <sblachmann@gmail.com> Cc: freebsd-hackers@freebsd.org Subject: Re: Reasons for keeping sc(4) and libvgl ? Message-ID: <20211126171617.f57c65e9c4dbdb0d1a2863c0@bidouilliste.com> In-Reply-To: <CACc-My0%2B5zi9bsMpLWsOMmP8uiatTCBiJcvkOAS_3%2BXfrNWMvQ@mail.gmail.com> References: <20211126160454.3eb827365a02103169ab9adc@bidouilliste.com> <CACc-My0%2B5zi9bsMpLWsOMmP8uiatTCBiJcvkOAS_3%2BXfrNWMvQ@mail.gmail.com>
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On Fri, 26 Nov 2021 16:45:17 +0100 Stefan Blachmann <sblachmann@gmail.com> wrote: > Main technical reasons why I consider sc(4) essential: > > - vt/vesa.ko break suspend/resume on nvidia cards. To make > suspend/resume work on computers with nvidia, it is necessary to build > a kernel *without* vt/vesa modules. See > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=253733 I'm not sure I understand your report, does the system suspend/resume fine if you use vt or not ? To me it seems that the problem is when you have vt(4) in the kernel but uses sc(4). > - vt is so horridly buggy that it is no fun to use it at all if one is > accustomed to well-working, bugfree sc(4). Just one example: > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=211922 Oh yes, one scroll bug that I even can't reproduce locally clearly makes vt(4) 'horridly buggy'. > > The hate and disregard against sc(4) and against nvidia and the > arrogance that can be observed from some FreeBSD core guys amazes me > again and again. > I often wonder why Nvidia has not already dropped FreeBSD support due > to such attitudes. > > > On 11/26/21, Emmanuel Vadot <manu@bidouilliste.com> wrote: > > > > Hello all, > > > > I'm currently re-implementing the framebuffer code in linuxkpi for > > drm-kmod and this made me look at sc(4), vt(4) and friends. > > > > So I looked at what sc could do and vt couldn't and vice-versa. > > > > What sc(4) can't do : > > > > - Work with EFI firmware. > > - Support UTF-8 > > - Maybe other things but everything here is EFI-based so let me know. > > > > What vt(4) can't do : > > > > - You can't get the modes or adapter info with vidcontrol. > > vidcontrol -i mode is really made for anything vesa based as it > > iterates on all the modes and display them if present. > > In the modern world (EFI), we don't have that, EFI GOP doesn't > > support changing resolution after ExitBootService was called so there > > is only one "mode". I could possibly hack some patch so vidcontrol -i > > mode/adapter would work and display the current framebuffer info if > > people wants (but I honestly doubt that vidcontrol is useful at all in > > an EFI world). > > - "Blanking" screen doesn't do what you think it does. For some reason > > in vt(4) we just write black colors on the screen and ignore the blank > > mode passed in the ioctl. > > Now again, blanking/dpms/blah isn't possible with efi_fb but it make > > sense to fix vt(4) and drm-kmod so it calls the drm module blanking > > function, I'll work on that next week. > > - There is no screensaver, again see notes above for dpms but do > > people still use sc(4) just for the screensaver ?? > > - Maybe other things, please let me know. > > > > For libvgl it probably made sense back in the 90s but does it now ?? > > > > Based on my small list I don't see any good reason to keep sc(4) but > > maybe I've missed something bigger so please let me know. > > > > P.S.: I'm really not interested by people saying stuff like > > "I've always used sc(4), it works for me don't touch it" > > without some technical argument. > > > > Cheers, > > > > -- > > Emmanuel Vadot <manu@bidouilliste.com> <manu@freebsd.org> > > > > -- Emmanuel Vadot <manu@bidouilliste.com> <manu@freebsd.org>
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