From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH 5/7] ARM: EXYNOS4: Add support external GIC Date: Tue, 11 Oct 2011 14:30:48 +0100 Message-ID: <4E944508.4050202@arm.com> References: <1308555258-4322-1-git-send-email-chaos.youn@samsung.com> <1308555258-4322-6-git-send-email-chaos.youn@samsung.com> <4E8C61C4.9090709@arm.com> <00ec01cc83f1$81f84430$85e8cc90$%kim@samsung.com> <4E8D645D.4020601@arm.com> <4E8ECA1B.5010005@arm.com> <20111007151646.GA2398@mudshark.cambridge.arm.com> <4E92ECD1.2010303@arm.com> <00b901cc8810$8353e730$89fbb590$%youn@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Return-path: Received: from service87.mimecast.com ([91.220.42.44]:43199 "HELO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752888Ab1JKNa5 convert rfc822-to-8bit (ORCPT ); Tue, 11 Oct 2011 09:30:57 -0400 In-Reply-To: <00b901cc8810$8353e730$89fbb590$%youn@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Changhwan Youn Cc: Will Deacon , "linux-samsung-soc@vger.kernel.org" , 'Arnd Bergmann' , 'Kukjin Kim' , "ben-linux@fluff.org" , 'Russell King' , "linux-arm-kernel@lists.infradead.org" Hi Changwan, On 11/10/11 13:22, Changhwan Youn wrote: >> Kukjin, could you please comment on the presence of a common memory >> region for the distributor? This seem quite odd... > > Some registers in Distributor are banked for PPI and SGI support (banked interrupts). > The register for pending and enable status of these interrupts are > banked. Right, that explains it then. > Marc, I think the approach in your patch is much better than mine if it doesn't hurt > the performance of other platforms which use the common gic code. It probably doesn't hurt the general case too much (I expect a bit more pressure on the d-cache because of the per-cpu stuff, but nothing to be too worried about). > I'll re-work the exynos4 interrupt code based on your patch though > I'm not sure that it's possible to be merged in merge window. My main concern at the moment is that mainline is broken as far as EXYNOS4 is concerned (there's a race with the EOI hook), so that should get fixed first. Cheers, M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Tue, 11 Oct 2011 14:30:48 +0100 Subject: [PATCH 5/7] ARM: EXYNOS4: Add support external GIC In-Reply-To: <00b901cc8810$8353e730$89fbb590$%youn@samsung.com> References: <1308555258-4322-1-git-send-email-chaos.youn@samsung.com> <1308555258-4322-6-git-send-email-chaos.youn@samsung.com> <4E8C61C4.9090709@arm.com> <00ec01cc83f1$81f84430$85e8cc90$%kim@samsung.com> <4E8D645D.4020601@arm.com> <4E8ECA1B.5010005@arm.com> <20111007151646.GA2398@mudshark.cambridge.arm.com> <4E92ECD1.2010303@arm.com> <00b901cc8810$8353e730$89fbb590$%youn@samsung.com> Message-ID: <4E944508.4050202@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Changwan, On 11/10/11 13:22, Changhwan Youn wrote: >> Kukjin, could you please comment on the presence of a common memory >> region for the distributor? This seem quite odd... > > Some registers in Distributor are banked for PPI and SGI support (banked interrupts). > The register for pending and enable status of these interrupts are > banked. Right, that explains it then. > Marc, I think the approach in your patch is much better than mine if it doesn't hurt > the performance of other platforms which use the common gic code. It probably doesn't hurt the general case too much (I expect a bit more pressure on the d-cache because of the per-cpu stuff, but nothing to be too worried about). > I'll re-work the exynos4 interrupt code based on your patch though > I'm not sure that it's possible to be merged in merge window. My main concern at the moment is that mainline is broken as far as EXYNOS4 is concerned (there's a race with the EOI hook), so that should get fixed first. Cheers, M. -- Jazz is not dead. It just smells funny...