[RFC 4/9] PCI: hold the rescan mutex when scanning for the first time

From: Bartosz Golaszewski <brgl@bgdev.pl>
To: "Kalle Valo" <kvalo@kernel.org>,
	"David S . Miller" <davem@davemloft.net>,
	"Eric Dumazet" <edumazet@google.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Paolo Abeni" <pabeni@redhat.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Bjorn Andersson" <andersson@kernel.org>,
	"Konrad Dybcio" <konrad.dybcio@linaro.org>,
	"Catalin Marinas" <catalin.marinas@arm.com>,
	"Will Deacon" <will@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Jernej Skrabec" <jernej.skrabec@gmail.com>,
	"Chris Morgan" <macromorgan@hotmail.com>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Geert Uytterhoeven" <geert+renesas@glider.be>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Neil Armstrong" <neil.armstrong@linaro.org>,
	"Nícolas F . R . A . Prado" <nfraprado@collabora.com>,
	"Marek Szyprowski" <m.szyprowski@samsung.com>,
	"Peng Fan" <peng.fan@nxp.com>,
	"Robert Richter" <rrichter@amd.com>,
	"Dan Williams" <dan.j.williams@intel.com>,
	"Jonathan Cameron" <Jonathan.Cameron@huawei.com>,
	"Terry Bowman" <terry.bowman@amd.com>,
	"Kuppuswamy Sathyanarayanan"
	<sathyanarayanan.kuppuswamy@linux.intel.com>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
	"Huacai Chen" <chenhuacai@kernel.org>,
	"Alex Elder" <elder@linaro.org>,
	"Srini Kandagatla" <srinivas.kandagatla@linaro.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [RFC 4/9] PCI: hold the rescan mutex when scanning for the first time
Date: Thu,  4 Jan 2024 14:01:18 +0100	[thread overview]
Message-ID: <20240104130123.37115-5-brgl@bgdev.pl> (raw)
In-Reply-To: <20240104130123.37115-1-brgl@bgdev.pl>

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

With the introduction of the power sequencing drivers that will be able
to trigger the port rescan, we need to hold the rescan mutex during the
initial pci_host_probe() too or the two could get in each other's way.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/pci/probe.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b7335be56008..957f7afee7ba 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -3122,7 +3122,9 @@ int pci_host_probe(struct pci_host_bridge *bridge)
 	struct pci_bus *bus, *child;
 	int ret;
 
+	pci_lock_rescan_remove();
 	ret = pci_scan_root_bus_bridge(bridge);
+	pci_unlock_rescan_remove();
 	if (ret < 0) {
 		dev_err(bridge->dev.parent, "Scanning root bridge failed");
 		return ret;
-- 
2.40.1

