Re: [PATCH v2 3/3] PCI: imx6: limit DBI register length

From: Andrey Smirnov
Date: Tue Nov 27 2018 - 20:28:29 EST


On Tue, Nov 27, 2018 at 5:12 PM Fabio Estevam <festevam@xxxxxxxxx> wrote:
>
> Hi Andrey,
>
> On Tue, Nov 27, 2018 at 10:57 PM Andrey Smirnov
> <andrew.smirnov@xxxxxxxxx> wrote:
>
> > Could this be a regression? Prior to 415b6185c541 ("PCI: imx6: Fix
> > config read timeout handling") all of the imprecise aborts were caught
> > and handled via no-op handler. I did an experiment on i.MX6Q board
> > that I have (ZII RDU2) and adding a simple no-op for imprecise aborts
> > via
> >
> > hook_fault_code(16 + 6, imx6q_pcie_no_op_handler, SIGBUS, 0,
> > "imprecise external abort");
> >
> > seems to "resolve" this problem:
>
> Please check https://patchwork.kernel.org/patch/9720313/
>
> This commit fixed a kernel crash on mx6q boards with a PCI switch.
>
> So we can't go back to the simple no-op.

It's probably not exactly clear form my message, but I wasn't
proposing to go back to a no-op. What I had in mind is having a no-op
handler for imprecise aborts _alongside_ the non-linefetch handlers
that is already there when running against i.MX6Q type of the IP
block.

Thanks,
Andrey Smirnov