From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH] ARM: add get_user() support for 8 byte types Date: Mon, 19 Nov 2012 14:48:06 +0000 Message-ID: <20121119144806.GO3332@n2100.arm.linux.org.uk> References: <1352495853-9790-1-git-send-email-rob.clark@linaro.org> <201211151339.08016.arnd@arndb.de> <201211151439.41393.arnd@arndb.de> <20121119143236.GA3296@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:45406 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751994Ab2KSOs0 (ORCPT ); Mon, 19 Nov 2012 09:48:26 -0500 Content-Disposition: inline In-Reply-To: <20121119143236.GA3296@intel.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Cc: Arnd Bergmann , Rob Clark , patches@linaro.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jamie Lokier On Mon, Nov 19, 2012 at 04:32:36PM +0200, Ville Syrj=E4l=E4 wrote: > On Thu, Nov 15, 2012 at 02:39:41PM +0000, Arnd Bergmann wrote: > > On Thursday 15 November 2012, Rob Clark wrote: > > > > I still haven't heard a conclusive argument why we need to use = get_user() > > > > rather than copy_from_user() in the DRM code. Is this about a f= ast path > > > > where you want to shave off a few cycles for each call, or does= this > > > > simplify the code structure, or something else? > > >=20 > > > well, it is mostly because it seemed like a good idea to first tr= y to > > > solve the root issue, rather than having to fix things up in each > > > driver when someone from x86-world introduces a 64b get_user().. > >=20 > > As pointed out by hpa earlier, x86-32 doesn't have a 64b get_user > > either. I don't think we have a lot of drivers that are used only > > on 64-bit x86 and on 32-bit ARM but not on 32-bit x86. >=20 > Ouch. I didn't realize that x86-32 doesn't have it. All the systems > where I've run the new code are 64bit so I never noticed the problem. >=20 > I see there was a patch [1] posted a long time ago to implement 64bit > get_user() on x86-32. I wonder what happened to it? >=20 > [1] https://lkml.org/lkml/2004/4/20/96 Wonderful lkml.org after four "Negotiating SSL connection..." messages gives me under elinks... Unable to retrieve https://lkml.org/lkml/2004/4/20/96: Error reading from socket and with wget: $ wget https://lkml.org/lkml/2004/4/20/96 --2012-11-19 14:47:16-- https://lkml.org/lkml/2004/4/20/96 Resolving lkml.org... 87.253.128.182 Connecting to lkml.org|87.253.128.182|:443... connected. HTTP request sent, awaiting response... No data received. Retrying. --2012-11-19 14:47:19-- (try: 2) https://lkml.org/lkml/2004/4/20/96 Connecting to lkml.org|87.253.128.182|:443... connected. HTTP request sent, awaiting response... No data received. Retrying. --2012-11-19 14:47:22-- (try: 3) https://lkml.org/lkml/2004/4/20/96 Connecting to lkml.org|87.253.128.182|:443... connected. HTTP request sent, awaiting response... No data received. Retrying. --2012-11-19 14:47:26-- (try: 4) https://lkml.org/lkml/2004/4/20/96 Connecting to lkml.org|87.253.128.182|:443... connected. HTTP request sent, awaiting response... No data received. Retrying. =2E.. what a wonderful site... please choose another LKML archive, preferably one which works. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html