From: Xilin Wu <sophon@radxa.com>
To: "Manivannan Sadhasivam" <mani@kernel.org>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
"Rob Herring" <robh@kernel.org>,
"Bjorn Helgaas" <bhelgaas@google.com>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>,
linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, Xilin Wu <sophon@radxa.com>
Subject: [PATCH] PCI: qcom: Restrict PERST# parsing to PCI bridge nodes
Date: Thu, 07 May 2026 22:18:31 +0800 [thread overview]
Message-ID: <20260507-fix-qcom-pcie-parse-perst-v1-1-79bdcce38eeb@radxa.com> (raw)
Commit 2fd60a2edb83 ("PCI: qcom: Parse PERST# from all PCIe bridge
nodes") extended PERST# parsing below the Root Port, so that downstream
PCIe switch bridge nodes can describe their own PERST# GPIOs.
However, the implementation recurses into every available child node. A
PCI hierarchy may contain non-bridge child nodes with unrelated
"reset-gpios" properties, such as an Ethernet PHY below an MDIO bus. If
such a reset GPIO is provided by a PCI endpoint GPIO controller, the
endpoint has not been enumerated while the host bridge is still probing.
Trying to acquire that GPIO then returns -EPROBE_DEFER and the Root Port
probe is deferred indefinitely.
Only recurse into child nodes that are PCI bridge/bus nodes. Keep parsing
the Root Port passed by qcom_pcie_parse_port(), but filter descendants to
nodes with device_type = "pci" and either a bus-range property or an
explicit PCI bridge class compatible.
Fixes: 2fd60a2edb83 ("PCI: qcom: Parse PERST# from all PCIe bridge nodes")
Signed-off-by: Xilin Wu <sophon@radxa.com>
---
drivers/pci/controller/dwc/pcie-qcom.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index af6bf5cce65b..5e0c31cc32a0 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1693,7 +1693,16 @@ static const struct pci_ecam_ops pci_qcom_ecam_ops = {
}
};
-/* Parse PERST# from all nodes in depth first manner starting from @np */
+static bool qcom_pcie_is_bridge_node(struct device_node *np)
+{
+ if (!of_node_is_type(np, "pci"))
+ return false;
+
+ return of_property_present(np, "bus-range") ||
+ of_device_is_compatible(np, "pciclass,0604");
+}
+
+/* Parse PERST# from all PCIe bridge nodes starting from @np */
static int qcom_pcie_parse_perst(struct qcom_pcie *pcie,
struct qcom_pcie_port *port,
struct device_node *np)
@@ -1731,6 +1740,9 @@ static int qcom_pcie_parse_perst(struct qcom_pcie *pcie,
parse_child_node:
for_each_available_child_of_node_scoped(np, child) {
+ if (!qcom_pcie_is_bridge_node(child))
+ continue;
+
ret = qcom_pcie_parse_perst(pcie, port, child);
if (ret)
return ret;
---
base-commit: 735d2f48cadaa9a87e7c7601667878de70c771c5
change-id: 20260507-fix-qcom-pcie-parse-perst-a882f580a658
Best regards,
--
Xilin Wu <sophon@radxa.com>
next reply other threads:[~2026-05-07 14:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-07 14:18 Xilin Wu [this message]
2026-05-15 17:41 ` [PATCH] PCI: qcom: Restrict PERST# parsing to PCI bridge nodes Manivannan Sadhasivam
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