From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [Fwd: Re: Wondering about cirris and stdvga] Date: Fri, 18 Nov 2016 23:31:48 +0100 Message-ID: <1479508308.3832.88.camel@citrix.com> References: <1479500348.16973.1.camel@redhat.com> <1479506264.3832.72.camel@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2017011588138201471==" Return-path: Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1c7rhN-0001c8-Nn for xen-devel@lists.xenproject.org; Fri, 18 Nov 2016 22:31:57 +0000 In-Reply-To: <1479506264.3832.72.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: xen-devel Cc: Stefano Stabellini , Ian Jackson , Paul Durrant , ajax@redhat.com, xen-devel , "anthony.perard" , Roger Pau Monne List-Id: xen-devel@lists.xenproject.org --===============2017011588138201471== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-Ywmmf+rnLXHDeeqnn2bV" --=-Ywmmf+rnLXHDeeqnn2bV Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable > On Fri, 2016-11-18 at 15:19 -0500, Adam Jackson wrote: > >=C2=A0On Fri, 2016-11-18 at 13:32 -0500, Konrad Rzeszutek Wilk wrote: > > On Fri, Nov 18, 2016 at 06:08:57PM +0000, Ian Jackson wrote: > > > > performance wise, that cirrus is broken and impossible to > > > > fix (because it is the hardware that it's emulating that was > > > > broken), > > > > that stdvga enables better screen resolution in guests, etc. > > >=20 > > > The "broken and impossible to fix" sounds like FUD TBH. >=20 > The "fear" bit, perhaps; it is arguably frightening that we continue > to > emulate in 2016 a=C2=A0chip that was inadequate in 1996. In my opinion > about > cirrus being broken, however, I am neither uncertain nor in doubt. >=20 Thanks Konrad for poking Adam, and thanks Adam for chiming in so quickly. > > > I wouldn't want to change the default just because Wayland is > > > broken. > > > Wayland should be fixed. >=20 > You should want to change the default because it is bad, even for X. >=20 In principle, I'm all with Ian's, and I think that's true for pretty much everyone. And in fact, I was really hesitant to start a discussion like this basing on: 1) another project's bug and 2) rumors (as Ian says, and he's right again) and incomplete knowledge. Then, poking around a bit more, and talking with Konrad, we had the feeling that those that were only rumors to us (well, to me), may actually be more than just that... which indeed seems to be what Adam is teaching us here. :-) > > CCing Adam Jackson who I hope can enlighten us on the technical > > parts of Xorg. > >=20 > > I am really interested in knowing the technical merits > > of the stdvga vs cirrus and I hope to understand what the Xorg > > maintainer(s) have in mind. >=20 > The cirrus chip that qemu happens to emulate is trash. It can't do > 32bpp, it can't do modes larger than 2048 wide, it can't do more than > 4M of VRAM. We could of course extend the qemu emulation to be more > capable; doing so would require updating every guest to know about > these enhancements, though. >=20 > stdvga, as it has none of the above problems, is _today_ uniformly > better than cirrus. It is still perhaps less awesome than one would > like (no idea how multihead is expected to work for example), but > there > is no world in which stdvga is worse than cirrus. >=20 Ok. These seems very good reasons to me. Then of course I'm no maintainer, so it's someone else's call... Hopefully, we at least gathered some useful insights. :-) Thanks and Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-Ywmmf+rnLXHDeeqnn2bV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJYL4FUAAoJEBZCeImluHPuoiMQANaR0s3I3mQV6Xl+ZZtCkHTq CQ+Gpc1pMnyL0wpA9H2HPQVXMMR/DR1yzKWKgoiPpNhZAheZciBUdkswE11CaU79 By2tJHBzgL9KSmZJtpr8kMaYVNDo0/Qo910y0iPTWOHiXUiiQrXwkotQew7Pu85C pIvWtfRbCimwe35/ciaxrSoUnmvh5KA4I3O1afgleeWoMPhLTG9ysAqBDGv5cbAD 5zTVCnbTrS4itCpCG2q1H3OvxhBsN9x0wFyWwhTzH+d32p8aup4OIXQvMbnct8NB nsMAz0rtLC/+l7JgQunol9bw+GnEDKbx7SA/gVMCdKJwmuztIXHkmzJIQB9QVcqm y8rZRTY4nwpsgmNlZiIWapoIhi5lhuWlhdH2DlIlJ510Q/6yZED2ValawgAN2x6b 9LpdEI8NN/UT7cb9SXn3R40eMY7S9SQj1PDyVNwGzzgJYWj/C4c7dXPFHB2lNlyE kas5HqPhX5RzkT/nh/4taIVa4WNv3xrS4x2+iOQUbQtjWexCu1S0JyexZH98Ypiw QFnOUYMql8w6XX0b9v4/ERx5SJ1nqRgDeV+2yDJLhkV6S9TpaQWOPgtHpIo++NcZ l9QhRfUAkMx2THYMECeyP+wzscupOcNHCssvf2fatuzya7ktRAzBQmTU6MXVikq3 SErKkRKe76GAimsScIOL =zC/Z -----END PGP SIGNATURE----- --=-Ywmmf+rnLXHDeeqnn2bV-- --===============2017011588138201471== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============2017011588138201471==--