On Wed, Jun 26, 2024 at 12:10:41AM +0200, Jan Kiszka wrote: > From: Kishon Vijay Abraham I <kishon@xxxxxx> > > 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@xxxxxx> > Signed-off-by: Achal Verma <a-verma1@xxxxxx> > Link: https://lore.kernel.org/linux-pci/20210325090026.8843-7-kishon@xxxxxx/ Please drop the above. It needs to be mentioned as the v1 below the tear-line. > Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx> > Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > --- > > 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.
