[PATCH] PCI: endpoint: Fix WARN() when an endpoint driver is removed

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
To: kishon@ti.com, lpieralisi@kernel.org, kw@linux.com, bhelgaas@google.com
Cc: linux-pci@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Subject: [PATCH] PCI: endpoint: Fix WARN() when an endpoint driver is removed
Date: Tue, 21 Jun 2022 21:11:47 +0900	[thread overview]
Message-ID: <20220621121147.3971001-1-yoshihiro.shimoda.uh@renesas.com> (raw)

Add pci_epc_nop_release() for epc->dev.release. Otherwise,
WARN() happened when a PCIe endpoint driver is removed.

 Device 'e65d0000.pcie-ep' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.
 WARNING: CPU: 0 PID: 139 at drivers/base/core.c:2232 device_release+0x78/0x8c

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/pci/endpoint/pci-epc-core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 3bc9273d0a08..cb533821b072 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -746,6 +746,10 @@ void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc)
 }
 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy);
 
+static void pci_epc_nop_release(struct device *dev)
+{
+}
+
 /**
  * __pci_epc_create() - create a new endpoint controller (EPC) device
  * @dev: device that is creating the new EPC
@@ -779,6 +783,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
 	device_initialize(&epc->dev);
 	epc->dev.class = pci_epc_class;
 	epc->dev.parent = dev;
+	epc->dev.release = pci_epc_nop_release;
 	epc->ops = ops;
 
 	ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
-- 
2.25.1

