From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher James Halse Rogers Subject: Re: [PATCH 1/3] drm: Send pending vblank events before disabling vblank. Date: Wed, 27 Apr 2011 18:58:39 +1000 Message-ID: <1303894719.15750.13.camel@Ed> References: <1303884659-739-1-git-send-email-christopher.halse.rogers@canonical.com> <1303893156.5633.126.camel@thor.local> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0254089321==" Return-path: Received: from adelie.canonical.com (adelie.canonical.com [91.189.90.139]) by gabe.freedesktop.org (Postfix) with ESMTP id 0C4BD9E7AE for ; Wed, 27 Apr 2011 01:58:47 -0700 (PDT) In-Reply-To: <1303893156.5633.126.camel@thor.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Michel =?ISO-8859-1?Q?D=E4nzer?= Cc: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============0254089321== Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-h5A0H8Cr7KavB9qtWt6d" --=-h5A0H8Cr7KavB9qtWt6d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2011-04-27 at 10:32 +0200, Michel D=C3=A4nzer wrote: > On Mit, 2011-04-27 at 16:10 +1000, christopher.halse.rogers@canonical.com= wrote: > > From: Christopher James Halse Rogers > >=20 > > This is the least-bad behaviour. It means that we signal the > > vblank event before it actually happens, but since we're disabling > > vblanks there's no guarantee that it will *ever* happen otherwise. >=20 > This may indeed be the best we can do for events that are pending when > the CRTC is disabled[0], but I can't see anything that would prevent new > events from getting scheduled (or synchronous vblank waits from timing > out) while the CRTC is disabled? >=20 > [0] Though it might unnecessarily send events prematurely when the CRTC > is just disabled temporarily, e.g. as part of a modeset. >=20 >=20 > Also, this patch won't seem to help at all for other drivers which don't > call drm_vblank_off() directly when disabling a CRTC. This is true. On the other hand, the other drivers don't wedge the vblank code into a state where vblanks cannot be re-enabled. So it's only a problem when disabling one of 2+ monitors on those drivers, whereas it's easily triggerable on single monitor systems on intel.=20 >=20 > Maybe it would be possible to move those calls to core code, and/or only > force sending out events when the CRTC isn't just getting disabled > temporarily. >=20 As in: have the core modesetting code call drm_vblank_off before making the driver-specific calls when disabling a crtc? I'll look into it - that would appear to be a more general solution. It would be nice if the OML_sync_control had been written with a less than laser-like focus on the single monitor case, too. :/ --=-h5A0H8Cr7KavB9qtWt6d Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAABCAAGBQJNt9q/AAoJEBUHnPSAqAyg8LIIAIb34+s0gHqwRbAI0K/4sRdp b5cpIvpLcQN0Wneu7j2HXG9x8w/k5jO7gPG6VlFeJSHaXZTgAz9TWZZHmNcpsFAn PjTNB9ClZG/cZiJKswmdwwVWiQG5XUZhbwlFDNRa2K9JxI9orW4h6KIosxF+5Pis HxlDg+uGbbV2dYdkQ69LAUz0xC6gzBBfTAmfzB7grk2h9ErinSQiTldmLxVhCABv Kh+ELbuthRnLrY1c+5+B3Yx3Cuf5qdLkBvzqopWjZT/R3K+F/liVWg+iX7U/mAx7 u+ITo+1/7DHcnSDORKoakwrKDldMcJJeVsGjq0FRSmpn5VVYnMYpX0PgS3I/0/M= =6l95 -----END PGP SIGNATURE----- --=-h5A0H8Cr7KavB9qtWt6d-- --===============0254089321== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel --===============0254089321==--