Return-path: Received: from bar.sig21.net ([80.81.252.164]:46210 "EHLO bar.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751520AbaLHQuc (ORCPT ); Mon, 8 Dec 2014 11:50:32 -0500 Date: Mon, 8 Dec 2014 17:50:16 +0100 From: Johannes Stezenbach To: Catalin Marinas Cc: Russell King , "brcm80211-dev-list@broadcom.com" , linux-wireless , "linux-kernel@vger.kernel.org" , Arend van Spriel , David Miller , "linux-arm-kernel@lists.infradead.org" Subject: Re: using DMA-API on ARM Message-ID: <20141208165016.GA28471@sig21.net> (sfid-20141208_175049_886037_446876CD) References: <5481794E.4050406@broadcom.com> <20141205183945.GE31222@e104818-lin.cambridge.arm.com> <20141205185303.GG31222@e104818-lin.cambridge.arm.com> <20141208125538.GA26983@sig21.net> <20141208155556.GL16185@e104818-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20141208155556.GL16185@e104818-lin.cambridge.arm.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Dec 08, 2014 at 03:55:57PM +0000, Catalin Marinas wrote: > On Mon, Dec 08, 2014 at 12:55:38PM +0000, Johannes Stezenbach wrote: > > On Fri, Dec 05, 2014 at 06:53:03PM +0000, Catalin Marinas wrote: > > > > > > BTW, if you really have a PL310-like L2 cache, have a look at some > > > patches (I've seen similar symptoms) and make sure your configuration is > > > correct: > > > > > > http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=6395/1 > > > > > > http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=6529/1 > > > > > > The first one is vexpress specific. The second one was eventually > > > discarded by Russell (I don't remember the reason, I guess it's because > > > SoC code is supposed to set the right bits in there anyway). In your > > > case, such bits may be set up by firmware, so Linux cannot fix anything > > > up. > > > > How do you avoid the unpredictable behavior mentioned in the > > PL310 TRM when the Shared Attribute Invalidate Enable bit is set? > > http://infocenter.arm.com/help/topic/com.arm.doc.ddi0246h/Ceggcfcj.html > > So you talk about "Shared Attribute _Invalidate_ Enable" (bit 13) while > I talk about "Shared Attribute _Override_ Enable" (bit 22). > > In addition, Shared _Invalidate_ behaviour can only be enabled if Shared > Attribute _Override_ Enable bit is not set. Yeah, I got confused, sorry for the noise. Thanks, Johannes