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From:   Andrey Smirnov <andrew.smirnov@gmail.com>
Date:   Tue, 27 Nov 2018 17:28:13 -0800
Message-ID: <CAHQ1cqFprD4k+aO_x-znEs6sXpx9jxih-moSuNZZ3dAKHuLpPw@mail.gmail.com>
Subject: Re: [PATCH v2 3/3] PCI: imx6: limit DBI register length
To:     Fabio Estevam <festevam@gmail.com>
Cc:     Stefan Agner <stefan@agner.ch>, Jingoo Han <jingoohan1@gmail.com>,
        gustavo.pimentel@synopsys.com,
        Lucas Stach <l.stach@pengutronix.de>,
        Trent Piepho <tpiepho@impinj.com>,
        Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Leonard Crestez <leonard.crestez@nxp.com>
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On Tue, Nov 27, 2018 at 5:12 PM Fabio Estevam <festevam@gmail.com> wrote:
>
> Hi Andrey,
>
> On Tue, Nov 27, 2018 at 10:57 PM Andrey Smirnov
> <andrew.smirnov@gmail.com> 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