From: Jim Quinlan <james.quinlan@broadcom.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: "open list:PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS"
<linux-pci@vger.kernel.org>,
Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
Mark Brown <broonie@kernel.org>,
"maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE"
<bcm-kernel-feedback-list@broadcom.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Rob Herring <robh@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Florian Fainelli <f.fainelli@gmail.com>,
"moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
<linux-rpi-kernel@lists.infradead.org>,
"moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 5/6] PCI: brcmstb: Add panic/die handler to RC driver
Date: Tue, 1 Dec 2020 15:12:54 -0500 [thread overview]
Message-ID: <CA+-6iNy0O8WJMm+z7QOEsMpGAj=-quBmbPwrZpgxo19kVB921g@mail.gmail.com> (raw)
In-Reply-To: <20201201180503.GA1321042@bjorn-Precision-5520>
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On Tue, Dec 1, 2020 at 1:05 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> On Mon, Nov 30, 2020 at 04:11:42PM -0500, Jim Quinlan wrote:
> > Whereas most PCIe HW returns 0xffffffff on illegal accesses and the like,
> > by default Broadcom's STB PCIe controller effects an abort. This simple
> > handler determines if the PCIe controller was the cause of the abort and if
> > so, prints out diagnostic info.
>
> What happens during enumeration? pci_bus_generic_read_dev_vendor_id()
> assumes a read of Vendor ID returns 0xffffffff if the device doesn't
> exist.
>
> I assume this case doesn't cause the abort you're referring to here,
> or nothing would work. I think this enumeration case results in PCIe
> Unsupported Request errors (PCIe r5.0, sec 2.3.2 implementation note).
Hi Bjorn,
Yes, our controller makes a special case to allow for config-space
accesses to the dev_id and vendor_id registers. even if the device is
missing. That being said, it will abort on any access if the link is
down.
However, the 7216-type SOCs bring PCIe error-reporting HW but also
have a mode where 0xffffffff is returned on improper accesses, just
like many other controllers. We are debating whether we should turn
this on by default.
Regards,
Jim Quinlan
Broadcom STB
>
> Bjorn
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next prev parent reply other threads:[~2020-12-01 20:13 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-30 21:11 [PATCH v2 0/6] brcmstb: add EP regulators and panic handler Jim Quinlan
2020-11-30 21:11 ` [PATCH v2 1/6] dt-bindings: PCI: Add bindings for Brcmstb EP voltage regulators Jim Quinlan
2020-12-09 14:01 ` Rob Herring
2021-01-04 22:12 ` Jim Quinlan
2021-01-05 14:01 ` Mark Brown
2021-01-05 15:09 ` Jim Quinlan
2021-01-05 15:33 ` Mark Brown
2021-01-07 22:31 ` Rob Herring
2020-11-30 21:11 ` [PATCH v2 2/6] PCI: brcmstb: Add control of EP voltage regulator(s) Jim Quinlan
2020-11-30 21:32 ` Florian Fainelli
2020-11-30 21:11 ` [PATCH v2 3/6] PCI: brcmstb: Do not turn off regulators if EP can wake up Jim Quinlan
2020-11-30 21:29 ` Florian Fainelli
2020-11-30 21:11 ` [PATCH v2 4/6] PCI: brcmstb: Give 7216 SOCs their own config type Jim Quinlan
2020-11-30 21:24 ` Florian Fainelli
2020-11-30 21:11 ` [PATCH v2 5/6] PCI: brcmstb: Add panic/die handler to RC driver Jim Quinlan
2020-11-30 21:28 ` Florian Fainelli
2020-12-01 18:05 ` Bjorn Helgaas
2020-12-01 20:12 ` Jim Quinlan [this message]
2021-01-06 19:19 ` Bjorn Helgaas
[not found] ` <CA+-6iNzARUT63Mv7qFzk_g5wep4v6aPuN8f8yjQcgozVcKhVTw@mail.gmail.com>
2021-01-06 19:57 ` Jim Quinlan
2021-01-06 23:11 ` Bjorn Helgaas
2020-11-30 21:11 ` [PATCH v2 6/6] PCI: brcmstb: check return value of clk_prepare_enable() Jim Quinlan
2020-11-30 21:24 ` Florian Fainelli
2021-01-06 19:19 ` [PATCH v2 0/6] brcmstb: add EP regulators and panic handler Bjorn Helgaas
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