Re: [PATCH] PCI: layerscape: Change back to the default error response behavior

From: Rob Herring
Date: Wed Sep 30 2020 - 11:08:13 EST


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.

> 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?

Rob