From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Anholt Subject: Re: [PATCH 9/9] drm/i915: swizzling support for snb/ivb Date: Fri, 11 Nov 2011 11:37:53 -0800 Message-ID: <87k476qwku.fsf@eliezer.anholt.net> References: <1320931087-1557-1-git-send-email-daniel.vetter@ffwll.ch> <1320931087-1557-10-git-send-email-daniel.vetter@ffwll.ch> <87sjluob6x.fsf@eliezer.anholt.net> <20111111172225.GB7295@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1934502367==" Return-path: In-Reply-To: <20111111172225.GB7295@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Daniel Vetter Cc: Daniel Vetter , intel-gfx List-Id: intel-gfx@lists.freedesktop.org --===============1934502367== Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" --=-=-= Content-Transfer-Encoding: quoted-printable On Fri, 11 Nov 2011 18:22:25 +0100, Daniel Vetter wrote: > On Fri, Nov 11, 2011 at 08:50:30AM -0800, Eric Anholt wrote: > > On Thu, 10 Nov 2011 14:18:07 +0100, Daniel Vetter wrote: > > > We have to do this manually. Somebody had a Great Idea. > > >=20 > > > Signed-Off-by: Daniel Vetter > >=20 > > People playing with this when not strictly required is scary to me. > > Manually swizzling was a world of hurt. I got to play with things like > > "when the management engine is enabled, it carves out the top N MB of > > one of the dimms, and the corresponding N MB of the other dimm doesn't > > get swizzled, and you lose". >=20 > Looks like yet another patch series of mine that scares away people ... >=20 > Would this patch be less scary when we have a test that slurps in the > entire ram to quickly diagnose such issues? We can then either revert this > or fix up the detection to not enable swizzling in such cases. >=20 > Also the manually swizzling is a world of hurt argument is pretty void: Up > to very recent kernels we've advertised bit9 swizzling on snb+ without any > swizzling actually going on. So userspace clearly doesn't rely on this > anymore (the issue was caught by running the pread tests in i-g-t). I was assuming you were working on this because you were planning on building something that *used* this swizzling. We removed all the userland because we never got it to actually work. --=-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEARECAAYFAk69eZEACgkQHUdvYGzw6veNxgCfTbWrIeBv5O+MvYxHl3VrnTae J9oAoI26aGpJZ90ghAgcSNrouMSuQlkx =6KJq -----END PGP SIGNATURE----- --=-=-=-- --===============1934502367== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx --===============1934502367==--