From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Cloos Subject: Re: [Linux-fbdev-devel] radeonfb lockup in .28-rc (bisected) Date: Mon, 03 Nov 2008 10:33:04 -0500 Message-ID: References: <1225152347.8004.49.camel@pasglop> <1225662539.8004.237.camel@pasglop> Mime-Version: 1.0 Return-path: In-Reply-To: <1225662539.8004.237.camel@pasglop> (Benjamin Herrenschmidt's message of "Mon, 03 Nov 2008 08:48:59 +1100") Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: benh@kernel.crashing.org Cc: linux-fbdev-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Andrew Morton , Linus Torvalds , "David S. Miller" , Krzysztof Halasa >>>>> "Benjamin" == Benjamin Herrenschmidt writes: >> is in play. It is probably spinning through all of the 2000000 possible >> udelay(10) calls. I don't think I ever gave it twenty seconds before >> giving up. And certainly not forty seconds, if the freeze happens after >> setting the DST_Y_X register. Benjamin> Well, setting DST_Y_X is what triggers the transfer. The above Benjamin> means that the FIFO isn't emptying (ie, the engine is locked up). I gave it another try over the weekend and let it sit for five minutes. The reset message never appeared. Benjamin> - We can blacklist that chip for imageblit (it's not a huge Benjamin> improvement on x86 anyway). No objections here. Benjamin> - We can be smart, reduce the timeout above, and "detect" the Benjamin> lockup, when it happens, reset the engine and disable the Benjamin> acceleration that locked up. Given Paul's report, that seems like the long term solution. Benjamin> Now, the problem is ... My second son was just born last Benjamin> wed. so I'm pretty unavailable right now. Congrats! Benjamin> Thus, for .29, I'm tempted to go for the simpler approach Benjamin> which is to blacklist M7's from imageblit acceleration. Again, that is fine by me. Otherwise I'll just leave the #if0 commit in my compile clone. -JimC -- James Cloos OpenPGP: 1024D/ED7DAEA6