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Date:   Wed, 19 Jan 2022 17:27:07 -0600
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     marek.vasut@gmail.com
Cc:     linux-pci@vger.kernel.org,
        Marek Vasut <marek.vasut+renesas@gmail.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Wolfram Sang <wsa@the-dreams.de>,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH v2 2/2] PCI: rcar: Return all Fs from read which
 triggered an exception
Message-ID: <20220119232707.GA975859@bhelgaas>
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On Tue, Jan 18, 2022 at 10:13:14AM -0600, Bjorn Helgaas wrote:
> On Mon, Jan 17, 2022 at 11:03:55PM +0100, marek.vasut@gmail.com wrote:

> > +	instr &= ~0xf;
> > +	if ((instr == 0xf57ff060 || instr == 0xf3bf8f60) &&
> > +	    (pc == (u32)&rcar_pci_read_reg_workaround_start + 4)) {
> > +		/*
> > +		 * If the instruction being executed was a read,
> > +		 * make it look like it read all-ones.
> > +		 */
> > +		instr = *(unsigned long *)(pc - 4);
> > +		reg = (instr >> 12) & 15;
> > +
> > +		if ((instr & 0x0c100000) == 0x04100000) {
> > +			if (instr & 0x00400000)
> > +				val = 255;
> > +			else
> > +				val = -1;
> 
> Can you please use PCI_SET_ERROR_RESPONSE() or something similar here
> to make this greppable?

I should have mentioned that PCI_SET_ERROR_RESPONSE() was added in the
current merge window, so it will appear in v5.17-rc1.

Bjorn