From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: [PATCH 00/14] Fix issues with ARMv6+v6k+v7 kernels Date: Wed, 9 Feb 2011 11:45:30 -0500 (EST) Message-ID: References: <20110117192050.GE23331@n2100.arm.linux.org.uk> <0557426516de482c1769a50fa0b5f17a@mail.gmail.com> <20110208164747.GD6188@n2100.arm.linux.org.uk> <78d0134576ace6be5874871076cf0c10@mail.gmail.com> <20110209003537.GQ20795@atomide.com> <54f225541194205f01fe9f03b5110d16@mail.gmail.com> <80a27c86473cf29a9fa5e68aa29eef46@mail.gmail.com> <20110209162421.GU20795@atomide.com> <20110209163204.GB11460@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from mail-qy0-f174.google.com ([209.85.216.174]:45566 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754203Ab1BIQpd (ORCPT ); Wed, 9 Feb 2011 11:45:33 -0500 Received: by qyj19 with SMTP id 19so1530217qyj.19 for ; Wed, 09 Feb 2011 08:45:32 -0800 (PST) In-Reply-To: <20110209163204.GB11460@n2100.arm.linux.org.uk> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Russell King - ARM Linux Cc: Tony Lindgren , Santosh Shilimkar , Dave Martin , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org On Wed, 9 Feb 2011, Russell King - ARM Linux wrote: > On Wed, Feb 09, 2011 at 08:24:21AM -0800, Tony Lindgren wrote: > > * Santosh Shilimkar [110209 01:59]: > > > > From: Dave Martin [mailto:dave.martin@linaro.org] > > > > > > > > You could also have a "v7+" unified kernel -- i.e., supporting > > > > OMAP3+4+SMP. > > > > This is what we currently do in Linaro, since we're focusing on v7 > > > > and above. > > > > > > > This sounds good way forward considering future OMAP architectures > > > as well. > > > > > > But I let Tony comment on this idea. > > > > AFAIK these issues will be hopefully sorted out by the time the > > next merge window opens. For the -rc cycle, disabling SMP in > > config if ARMv6 is selected should do the trick. > > That's not soo easy - as we don't know in the Kconfig whether we include > ARMv6 rather than ARMv6K. It's exactly the same problem I ran into which > inflated the v6v7 patchset. > > Maybe the best thing to do is: > > config CPU_32v6K > bool "Support ARM V6K processor extensions" if !SMP > depends on CPU_V6 || CPU_V7 > default y if SMP && !(ARCH_MX3 || ARCH_OMAP2) > > drop the ' && !(ARCH_MX3 || ARCH_OMAP2)' and just let people run into the > resulting undefined instruction traps if they try to run the kernel on > V6 non-K hardware. Not ideal, but I don't see any other 'simple' solution > to this. This should be good enough. We're looking for a temporary stopgate solution to prevent people from corrupting their data, and the real fix will be available in the next kernel. Nicolas From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicolas.pitre@linaro.org (Nicolas Pitre) Date: Wed, 9 Feb 2011 11:45:30 -0500 (EST) Subject: [PATCH 00/14] Fix issues with ARMv6+v6k+v7 kernels In-Reply-To: <20110209163204.GB11460@n2100.arm.linux.org.uk> References: <20110117192050.GE23331@n2100.arm.linux.org.uk> <0557426516de482c1769a50fa0b5f17a@mail.gmail.com> <20110208164747.GD6188@n2100.arm.linux.org.uk> <78d0134576ace6be5874871076cf0c10@mail.gmail.com> <20110209003537.GQ20795@atomide.com> <54f225541194205f01fe9f03b5110d16@mail.gmail.com> <80a27c86473cf29a9fa5e68aa29eef46@mail.gmail.com> <20110209162421.GU20795@atomide.com> <20110209163204.GB11460@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 9 Feb 2011, Russell King - ARM Linux wrote: > On Wed, Feb 09, 2011 at 08:24:21AM -0800, Tony Lindgren wrote: > > * Santosh Shilimkar [110209 01:59]: > > > > From: Dave Martin [mailto:dave.martin at linaro.org] > > > > > > > > You could also have a "v7+" unified kernel -- i.e., supporting > > > > OMAP3+4+SMP. > > > > This is what we currently do in Linaro, since we're focusing on v7 > > > > and above. > > > > > > > This sounds good way forward considering future OMAP architectures > > > as well. > > > > > > But I let Tony comment on this idea. > > > > AFAIK these issues will be hopefully sorted out by the time the > > next merge window opens. For the -rc cycle, disabling SMP in > > config if ARMv6 is selected should do the trick. > > That's not soo easy - as we don't know in the Kconfig whether we include > ARMv6 rather than ARMv6K. It's exactly the same problem I ran into which > inflated the v6v7 patchset. > > Maybe the best thing to do is: > > config CPU_32v6K > bool "Support ARM V6K processor extensions" if !SMP > depends on CPU_V6 || CPU_V7 > default y if SMP && !(ARCH_MX3 || ARCH_OMAP2) > > drop the ' && !(ARCH_MX3 || ARCH_OMAP2)' and just let people run into the > resulting undefined instruction traps if they try to run the kernel on > V6 non-K hardware. Not ideal, but I don't see any other 'simple' solution > to this. This should be good enough. We're looking for a temporary stopgate solution to prevent people from corrupting their data, and the real fix will be available in the next kernel. Nicolas