The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 42f9c66a6d0cc45758dab77233c5460e1cf003df # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025101638-carry-unwashed-bba6@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 42f9c66a6d0cc45758dab77233c5460e1cf003df Mon Sep 17 00:00:00 2001 From: Niklas Cassel cassel@kernel.org Date: Mon, 22 Sep 2025 16:08:25 +0200 Subject: [PATCH] PCI: tegra194: Reset BARs when running in PCIe endpoint mode
Tegra already defines all BARs except BAR0 as BAR_RESERVED. This is sufficient for pci-epf-test to not allocate backing memory and to not call set_bar() for those BARs. However, marking a BAR as BAR_RESERVED does not mean that the BAR gets disabled.
The host side driver, pci_endpoint_test, simply does an ioremap for all enabled BARs and will run tests against all enabled BARs, so it will run tests against the BARs marked as BAR_RESERVED.
After running the BAR tests (which will write to all enabled BARs), the inbound address translation is broken. This is because the tegra controller exposes the ATU Port Logic Structure in BAR4, so when BAR4 is written, the inbound address translation settings get overwritten.
To avoid this, implement the dw_pcie_ep_ops .init() callback and start off by disabling all BARs (pci-epf-test will later enable/configure BARs that are not defined as BAR_RESERVED).
This matches the behavior of other PCIe endpoint drivers: dra7xx, imx6, layerscape-ep, artpec6, dw-rockchip, qcom-ep, rcar-gen4, and uniphier-ep.
With this, the PCI endpoint kselftest test case CONSECUTIVE_BAR_TEST (which was specifically made to detect address translation issues) passes.
Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194") Signed-off-by: Niklas Cassel cassel@kernel.org Signed-off-by: Manivannan Sadhasivam mani@kernel.org Signed-off-by: Bjorn Helgaas bhelgaas@google.com Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250922140822.519796-7-cassel@kernel.org
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index fe418b9bfbb4..359d92dca86a 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -1941,6 +1941,15 @@ static irqreturn_t tegra_pcie_ep_pex_rst_irq(int irq, void *arg) return IRQ_HANDLED; }
+static void tegra_pcie_ep_init(struct dw_pcie_ep *ep) +{ + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); + enum pci_barno bar; + + for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) + dw_pcie_ep_reset_bar(pci, bar); +}; + static int tegra_pcie_ep_raise_intx_irq(struct tegra_pcie_dw *pcie, u16 irq) { /* Tegra194 supports only INTA */ @@ -2016,6 +2025,7 @@ tegra_pcie_ep_get_features(struct dw_pcie_ep *ep) }
static const struct dw_pcie_ep_ops pcie_ep_ops = { + .init = tegra_pcie_ep_init, .raise_irq = tegra_pcie_ep_raise_irq, .get_features = tegra_pcie_ep_get_features, };