Hi Rob and Kishon, > -----Original Message----- > From: Rob Herring <robh@xxxxxxxxxx> > Sent: 2020年9月30日 23:08 > To: Kishon Vijay Abraham I <kishon@xxxxxx> > Cc: Z.q. Hou <zhiqiang.hou@xxxxxxx>; PCI <linux-pci@xxxxxxxxxxxxxxx>; > linux-kernel@xxxxxxxxxxxxxxx; linux-arm-kernel > <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; Lorenzo Pieralisi > <lorenzo.pieralisi@xxxxxxx>; Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; M.h. > Lian <minghuan.lian@xxxxxxx>; Roy Zang <roy.zang@xxxxxxx>; Mingkai > Hu <mingkai.hu@xxxxxxx>; Leo Li <leoyang.li@xxxxxxx> > Subject: Re: [PATCH] PCI: layerscape: Change back to the default error > response behavior > > On Wed, Sep 30, 2020 at 8:29 AM Kishon Vijay Abraham I <kishon@xxxxxx> > wrote: > > > > Hi Hou, > > > > On 29/09/20 6:43 pm, Zhiqiang Hou wrote: > > > From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx> > > > > > > In the current error response behavior, it will send a SLVERR > > > response to device's internal AXI slave system interface when the > > > PCIe controller experiences an erroneous completion (UR, CA and CT) > > > from an external completer for its outbound non-posted request, > > > which will result in SError and crash the kernel directly. > > > This patch change back it to the default behavior to increase the > > > robustness of the kernel. In the default behavior, it always sends > > > an OKAY response to the internal AXI slave interface when the > > > controller gets these erroneous completions. And the AER driver will > > > report and try to recover these errors. > > > > I don't think not forwarding any error interrupts is a good idea. > > Interrupts would be fine. Abort/SError is not. I think it is pretty clear what the > correct behavior is for config accesses. I agree with Rob. > > > Maybe > > you could disable it while reading configuration space registers > > (vendorID and deviceID) and then enable error forwarding back? > > To add to the locking (or lack of) problems in config accesses? If take this approach, during the hole of CFG access, the error of MEM_rd will also not be forwarded, so it's not a reliable mechanism for user. Thanks, Zhiqiang > > Rob
