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Date:   Fri, 07 Jul 2023 10:25:09 +0800
From:   Li Chen <me@linux.beauty>
To:     "Tom Joseph" <tjoseph@cadence.com>,
        "Lorenzo Pieralisi" <lpieralisi@kernel.org>,
        =?UTF-8?Q?=22Krzysztof_Wilczy=C5=84ski=22?= <kw@linux.com>,
        "Rob Herring" <robh@kernel.org>,
        "Bjorn Helgaas" <bhelgaas@google.com>,
        "linux-pci" <linux-pci@vger.kernel.org>,
        "linux-kernel" <linux-kernel@vger.kernel.org>
Message-ID: <1892e2ae15f.f7e5dc061620757.4339091752690983066@linux.beauty>
In-Reply-To: 
Subject: PCI: cadence: Allow async probe
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From: Li Chen <lchen@ambarella.com>

I observed that on Ambarella SoC, which also utilizes
the Cadence controller, the boot time increases by 1
second when no endpoints (including switch) are connected
to PCIe. This increase is caused by cdns_pcie_host_wait_for_link.

Enabling async probe can eliminate this boot time increase.

I guess other platforms also has this issue.

Signed-off-by: Li Chen <lchen@ambarella.com>
---
 drivers/pci/controller/cadence/pcie-cadence-plat.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-plat.c b/drivers/pci/controller/cadence/pcie-cadence-plat.c
index e091fef9c919..5177f18e1dfc 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-plat.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-plat.c
@@ -174,6 +174,7 @@ static struct platform_driver cdns_plat_pcie_driver = {
 		.name = "cdns-pcie",
 		.of_match_table = cdns_plat_pcie_of_match,
 		.pm	= &cdns_pcie_pm_ops,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 	.probe = cdns_plat_pcie_probe,
 	.shutdown = cdns_plat_pcie_shutdown,
-- 
2.34.1