linux-kernel - [PATCH] PCI: qcom: Prevent GDSC power down on suspend

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Message-Id: <20260128-genpd_fix-v1-1-cd45a249d12f@oss.qualcomm.com>
Date: Wed, 28 Jan 2026 17:52:42 +0530
From: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
To: Manivannan Sadhasivam <mani@...nel.org>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Krzysztof Wilczyński <kwilczynski@...nel.org>,
        Rob Herring <robh@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
        Stanimir Varbanov <svarbanov@...sol.com>
Cc: linux-arm-msm@...r.kernel.org, linux-pci@...r.kernel.org,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
Subject: [PATCH] PCI: qcom: Prevent GDSC power down on suspend

Currently, the driver expects the devices to remain in D0 across system
suspend, but the genpd framework may still power down the associated
GDSC during suspend. When that happens, the PCIe link goes down and
cannot be recovered on resume.

Prevent genpd from turning off the PCIe GDSC by using
dev_pm_genpd_rpm_always_on() so that the power domain stays on while
the controller is suspended. This preserves the link state across
suspend/resume and avoids unrecoverable link failures.

Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Cc: stable@...r.kernel.org
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 5a318487b2b3f6c61d8f5b1fd5cdf2738a1f1dcd..314cf334a313dff35efaf0c023597e6eef483925 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -25,6 +25,7 @@
 #include <linux/pci.h>
 #include <linux/pci-ecam.h>
 #include <linux/pm_opp.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 #include <linux/phy/pcie.h>
@@ -2052,6 +2053,11 @@ static int qcom_pcie_suspend_noirq(struct device *dev)
 		pcie->suspended = true;
 	}
 
+	if (pcie->suspended)
+		dev_pm_genpd_rpm_always_on(dev, false);
+	else
+		dev_pm_genpd_rpm_always_on(dev, true);
+
 	/*
 	 * Only disable CPU-PCIe interconnect path if the suspend is non-S2RAM.
 	 * Because on some platforms, DBI access can happen very late during the

---
base-commit: 1f97d9dcf53649c41c33227b345a36902cbb08ad
change-id: 20260128-genpd_fix-3aa413d9a383

Best regards,
-- 
Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>