Return-path: Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:46890 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755486AbaLILyf (ORCPT ); Tue, 9 Dec 2014 06:54:35 -0500 Date: Tue, 9 Dec 2014 11:54:26 +0000 From: Catalin Marinas To: Russell King - ARM Linux Cc: Arend van Spriel , Arnd Bergmann , "linux-arm-kernel@lists.infradead.org" , brcm80211-dev-list , linux-wireless , "linux-kernel@vger.kernel.org" , Will Deacon , Hante Meuleman , "hauke@hauke-m.de" , David Miller , Marek Szyprowski Subject: Re: using DMA-API on ARM Message-ID: <20141209115425.GB31129@e104818-lin.cambridge.arm.com> (sfid-20141209_125452_609304_DA461F7D) References: <5481794E.4050406@broadcom.com> <2863746.4sUSEYqahB@wuerfel> <20141208160316.GM16185@e104818-lin.cambridge.arm.com> <5485D97D.1040404@broadcom.com> <5486CCBC.3@broadcom.com> <20141209102904.GJ11285@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20141209102904.GJ11285@n2100.arm.linux.org.uk> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, Dec 09, 2014 at 10:29:05AM +0000, Russell King - ARM Linux wrote: > On Tue, Dec 09, 2014 at 11:19:40AM +0100, Arend van Spriel wrote: > > The issue did not trigger overnight so it seems setting bit 22 > Attribute _Override_ Enable> solves the issue over here. Now the question is > > how to move forward with this. As I understood from Catalin this patch was > > not included as it was not considered responsibility of the linux kernel. > > It is preferable for firmware to configure the L2 cache appropriately, > which includes things like the prefetch offsets as well as feature bits > like bit 22. > > I think what I'll do is queue up a patch which adds a warning if bit 22 > is not set, suggesting that firmware is updated to set this bit. I'm fine with a (big) warning on this bit. But when you boot in secure mode on 32-bit, do we still have a read/modify/write sequence for L2X0_AUX_CTRL? A quick look at l2c310_enable() didn't reveal this (the code has changed since I proposed the bit 22 setting patch). -- Catalin