[PATCH] PCI: Honor firmware's device disabled status

From: Rob Herring <robh@kernel.org>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: Liu Peibao <liupeibao@loongson.cn>,
	Binbin Zhou <zhoubinbin@loongson.cn>,
	Huacai Chen <chenhuacai@loongson.cn>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] PCI: Honor firmware's device disabled status
Date: Fri, 10 Feb 2023 10:43:51 -0600	[thread overview]
Message-ID: <20230210164351.2687475-1-robh@kernel.org> (raw)

If a device has a firmware node (DT/ACPI), and the device is marked
disabled, that is currently ignored. Add a check for this condition
and bail out creating the pci_dev.

This assumes the config space for the device can still be accessed
because they already have by this point in order to identify the device.

Cc: Liu Peibao <liupeibao@loongson.cn>
Cc: Binbin Zhou <zhoubinbin@loongson.cn>
Cc: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Rob Herring <robh@kernel.org>
---
Please test if this works for Loongson.
---
 drivers/pci/probe.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 1779582fb500..b1d80c1d7a69 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1841,6 +1841,8 @@ int pci_setup_device(struct pci_dev *dev)
 
 	pci_set_of_node(dev);
 	pci_set_acpi_fwnode(dev);
+	if (dev->dev.fwnode && !fwnode_device_is_available(dev->dev.fwnode))
+		return -ENODEV;
 
 	pci_dev_assign_slot(dev);
 
-- 
2.39.1

