From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Vorontsov Subject: Re: [PATCH HACK] powerpc: quick hack to get a functional eHEA with hardirq preemption Date: Tue, 16 Sep 2008 15:59:47 +0400 Message-ID: <20080916115947.GA6995@oksana.dev.rtsoft.ru> References: <20080915100406.342e027a@bull.net> <48CE5684.4000506@de.ibm.com> <20080915151332.6a3a7c80@bull.net> Reply-To: avorontsov@ru.mvista.com Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1251 Cc: Thomas Klein , tklein@de.ibm.com, tinytim@us.ibm.com, Linux-rt , themann@de.ibm.com, netdev@vger.kernel.org, linux-kernel , jean-pierre.dion@bull.net, linux-ppc , raisch@de.ibm.com, gilles.carry@ext.bull.net To: Sebastien Dugue Return-path: Content-Disposition: inline In-Reply-To: <20080915151332.6a3a7c80@bull.net> Sender: linux-rt-users-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, Sep 15, 2008 at 03:13:32PM +0200, Sebastien Dugue wrote: [...] > > we are a bit worried about putting this into the mainstream part of non real > > time linux. > > Heck, I sure do not want this to be applied mainstream nor into any tree. > The sole purpose of this patch was to trigger some reaction from the people who > know the hardware and try to understand where the problem lies. > > > There interrupts work perfectly fine, and it was a bit of a > > challenge to get there for all cases / configurations / machines. > > Agreed, but the fact that it fails with hardirq preemption leads me to > believe (without any more knowledge about the harware) that there might be > something amiss with this driver (or the code concerning the XICS) > nevertheless. > > > > > Could you try to enable these changes only for RT-Linux via a real-time > > kconfig switch? > > Nope, this is just a quick hack that allows me to have a functional eHEA under > the rt kernel. I want to understand what the problem is: > > - Is the eHEA really delivering level interrupts to the XICS? > > - Is the XICS loosing interrupts when they are masked? There is a known bug in the -rt kernels, the bug causes handlers to lose edge interrupts. See this patch: http://lkml.org/lkml/2008/6/30/372 > - ...? -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2