From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Packard Subject: Re: gen7 missed IRQ workaround series. Date: Tue, 03 Jan 2012 15:38:25 -0800 Message-ID: <86lipomk5q.fsf@sumi.keithp.com> References: <1324594501-11029-1-git-send-email-eric@anholt.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1409853523==" Return-path: Received: from keithp.com (home.keithp.com [63.227.221.253]) by gabe.freedesktop.org (Postfix) with ESMTP id 378A69F649 for ; Tue, 3 Jan 2012 15:36:49 -0800 (PST) In-Reply-To: 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 , Eric Anholt Cc: intel-gfx@lists.freedesktop.org, "Dodonov, Eugeni" List-Id: intel-gfx@lists.freedesktop.org --===============1409853523== Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" --=-=-= Content-Transfer-Encoding: quoted-printable On Wed, 4 Jan 2012 00:04:18 +0100, Daniel Vetter wrote: > I kinda prefer Chris' approach of sticking with irqs, but backing it up > with a timer in the msec range. Can't find that patch though atm (iirc > it's in bugzilla somewhere). I think we've resolved that the interrupt arrives, but that it is not serialized wrt the memory write. So, what I'd love to see is whether waiting for the irq and then busy looping for 'a while' works. This would allow for long-running operations to idle the CPU and then hit the interrupt and spin until the memory write is recognized. Any solution which can leave operations unacknowledged for 'ms' timeframes seems like a potential for serious performance problems. Eric's simple spinning approach seems fine for the BLT ring which we don't use that often; something more complicated and yet not entirely timer-based might be more efficient for longer-running operations. =2D-=20 keith.packard@intel.com --=-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIVAwUBTwORcTYtFsjWk68qAQgLCRAAmc1aX7fOZjast95gKnd4Ib8j8fIR9Cxy UOMeBqUctMDqJJUTtYUNCdrdlcAzOGWXSNueF7Wacy6TFM3bWroK82pcRgTBj/b8 HT84fF/+m3Oc5N2GFp6g//j7CNshOL61CzjQSPHpZUSuDn3o0cP7J26Fg8VIcZOk F3tlaWo3qqVb5IpRYQHWW3pUc7TvP6xJPzFaPLqWkJu1lucysqLcNjP61bCjXcCE EEBrnwCs6fDy2kxKAuBrKc7bBdYFkH9xlCUgo9L4qVdXpy2LQBMYwIRjMJPjZdTJ GGjCjOICnZbtp6diPIdltmLo4fhzmV4nAXm+nYjvFYTpUaaWf7PU3RJ5tJe0Xp8R WGAI7jha6h8WA4H6RwYwvramXL06EfkGVY7/nTAHhBiotM6gKqlidOxXX7ybOXNz WzvmSdYHhLeXUT7URqIYugoPsGbfHhslKATbZgjRE8ctGnt0arX5uJ7/I509hLlC wWl7GWudUDHFYvjEQtaV9TQ5mrw14Ehqi2lCOsDKPvWp5IWeAV++6mrkvcFbxVtd UnLSu9eOa2rgSFD5pZvjoFkQxZCqJuSi1g3KsDrpFAm3lI36nMXR2ZGmywC/5s2Z QED1t4SDd9buNI9i/OPPVU3tpng+Qw6XQaz8zkR4YKPVxwq7rxuIQ7voPFBaCL1/ bj+hw58bCGk= =jLoR -----END PGP SIGNATURE----- --=-=-=-- --===============1409853523== 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 --===============1409853523==--