[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <f27ee4af-eda9-49b1-aab1-2477e5a79642@ti.com>
Date: Thu, 27 Jun 2024 17:54:44 +0530
From: Siddharth Vadapalli <s-vadapalli@...com>
To: Jan Kiszka <jan.kiszka@...mens.com>,
Krzysztof WilczyĆski
<kw@...ux.com>
CC: Lorenzo Pieralisi <lpieralisi@...nel.org>, Rob Herring <robh@...nel.org>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Kishon Vijay Abraham I
<kishon@...nel.org>,
Siddharth Vadapalli <s-vadapalli@...com>,
Vignesh
Raghavendra <vigneshr@...com>, Nishanth Menon <nm@...com>,
"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
Linux Kernel Mailing
List <linux-kernel@...r.kernel.org>,
linux-arm-kernel
<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH] PCI: keystone: Add workaround for Errata #i2037 (AM65x
SR 1.0)
On Wed, Jun 26, 2024 at 12:10:41AM +0200, Jan Kiszka wrote:
> From: Kishon Vijay Abraham I <kishon@...com>
>
> Errata #i2037 in AM65x/DRA80xM Processors Silicon Revision 1.0
> (SPRZ452D_July 2018_Revised December 2019 [1]) mentions when an
> inbound PCIe TLP spans more than two internal AXI 128-byte bursts,
> the bus may corrupt the packet payload and the corrupt data may
> cause associated applications or the processor to hang.
>
> The workaround for Errata #i2037 is to limit the maximum read
> request size and maximum payload size to 128 Bytes. Add workaround
> for Errata #i2037 here. The errata and workaround is applicable
> only to AM65x SR 1.0 and later versions of the silicon will have
> this fixed.
>
> [1] -> http://www.ti.com/lit/er/sprz452d/sprz452d.pdf
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@...com>
> Signed-off-by: Achal Verma <a-verma1@...com>
> Link: https://lore.kernel.org/linux-pci/20210325090026.8843-7-kishon@ti.com/
Please drop the above. It needs to be mentioned as the v1 below the
tear-line.
> Signed-off-by: Vignesh Raghavendra <vigneshr@...com>
> Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
> ---
>
> Needed for the IOT2050 PG1 variants. Pending downstream way too long.
>
> drivers/pci/controller/dwc/pci-keystone.c | 42 +++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
> index d3a7d14ee685..a04f1087ce91 100644
> --- a/drivers/pci/controller/dwc/pci-keystone.c
> +++ b/drivers/pci/controller/dwc/pci-keystone.c
> @@ -34,6 +34,11 @@
> #define PCIE_DEVICEID_SHIFT 16
[...]
>
> + static const struct pci_device_id am6_pci_devids[] = {
> + { PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_AM654X),
> + .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
> + { 0, },
> + };
>
> if (pci_is_root_bus(bus))
> bridge = dev;
> @@ -562,6 +578,32 @@ static void ks_pcie_quirk(struct pci_dev *dev)
> pcie_set_readrq(dev, 256);
> }
> }
> +
> + /*
> + * Memory transactions fail with PCI controller in AM654 PG1.0
> + * when MRRS is set to more than 128 Bytes. Force the MRRS to
> + * 128 Bytes in all downstream devices.
> + */
Comments on the v1 patch at:
https://lore.kernel.org/linux-pci/YF2K6+R1P3SNUoo5@rocinante/
haven't been addressed in this patch. Kindly update the patch based on
Krzysztof's feedback on the v1 patch.
> + if (pci_match_id(am6_pci_devids, bridge)) {
> + bridge_dev = pci_get_host_bridge_device(dev);
> + if (!bridge_dev && !bridge_dev->parent)
> + return;
> +
> + ks_pcie = dev_get_drvdata(bridge_dev->parent);
> + if (!ks_pcie)
> + return;
> +
> + val = ks_pcie_app_readl(ks_pcie, PID);
> + val &= RTL;
> + val >>= RTL_SHIFT;
> + if (val != AM6_PCI_PG1_RTL_VER)
> + return;
> +
> + if (pcie_get_readrq(dev) > 128) {
> + dev_info(&dev->dev, "limiting MRRS to 128\n");
> + pcie_set_readrq(dev, 128);
> + }
> + }
> }
> DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, ks_pcie_quirk);
Regards,
Siddharth.
Powered by blists - more mailing lists