> -----Original Message----- > From: Wood Scott-B07421 > Sent: Wednesday, October 01, 2014 8:44 AM > To: Guenter Roeck > Cc: Jojy Varghese; Benjamin Herrenschmidt; Paul Mackerras; Michael > Ellerman; linuxppc-dev@lists.ozlabs.org; linux-ker...@vger.kernel.org; > Guenter Roeck; Jia Hongtao-B38951 > Subject: Re: [PATCH] powerpc/fsl: Add support for pci(e) machine check > exception on E500MC / E5500 > > On Tue, 2014-09-30 at 08:50 -0700, Guenter Roeck wrote: > > On Mon, Sep 29, 2014 at 06:31:06PM -0500, Scott Wood wrote: > > > On Mon, 2014-09-29 at 23:03 +0000, Jojy Varghese wrote: > > > > > > > > On 9/29/14 12:06 PM, "Guenter Roeck" <li...@roeck-us.net> wrote: > > > > > > > > >Those are errors related to PCIe hotplug, and are seen with > > > > >unexpected PCIe device removals (triggered, for example, by > > > > >removing power from a PCIe adapter). > > > > >The behavior we see on E5500 is quite similar to the same > > > > >behavior on > > > > >E500: > > > > >If unhandled, the CPU keeps executing the same instruction over > > > > >and over again if there is an error on a PCIe access and thus > > > > >stalls. I don't know if this is considered an erratum or expected > > > > >behavior, but it is one we have to address since we have to be > > > > >able to handle that condition. > > > > > > The reason I ask is that the handling for e500 was described as an > > > erratum workaround. If it is an erratum it would be nice to know > > > the erratum number and the full list of affected chips. > > > > > My understanding, which may be wrong, was that this is expected > > behavior, at least for E5500. I actually thought I had seen it > > somewhere in the specification (response to PCIe errors), but I don't > recall where exactly. > > > > At least for my part I am not aware of an erratum. > > Jia Hongtao, can you comment here?
I did not find any related erratum either. > > > > > >Ultimately, we'll want > > > > >to > > > > >implement PCIe error handlers for the affected drivers, but that > > > > >will be a next step. > > > > > > For now can we at least print a ratelimited error message? I don't > > > like the idea of silently ignoring these errors. I suppose it's a > > > separate issue from extending the workaround to cover e500mc, though. > > > > > I don't really like the idea of printing an error message pretty much > > each time when an unexpected hotplug event occurs. > > Unexpected events seem like the sort of thing you'd want to log, but my > concern is that this might not be the only cause of PCI errors. > > -Scott > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
