[PATCH v2 24/40] PCI: dwc: Ensure FAST_LINK_MODE is cleared

From: Rob Herring <robh@kernel.org>
To: Bjorn Helgaas <bhelgaas@google.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: linux-pci@vger.kernel.org, Andy Gross <agross@kernel.org>,
	Binghui Wang <wangbinghui@hisilicon.com>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Dilip Kota <eswara.kota@linux.intel.com>,
	Fabio Estevam <festevam@gmail.com>,
	Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
	Jerome Brunet <jbrunet@baylibre.com>,
	Jesper Nilsson <jesper.nilsson@axis.com>,
	Jingoo Han <jingoohan1@gmail.com>,
	Jonathan Chocron <jonnyc@amazon.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Kevin Hilman <khilman@baylibre.com>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Kukjin Kim <kgene@kernel.org>,
	Kunihiko Hayashi <hayashi.kunihiko@socionext.com>,
	Lucas Stach <l.stach@pengutronix.de>,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Murali Karicheri <m-karicheri2@ti.com>,
	Neil Armstrong <narmstrong@baylibre.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Pratyush Anand <pratyush.anand@gmail.com>,
	Richard Zhu <hongxing.zhu@nxp.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Shawn Guo <shawnguo@kernel.org>, Shawn Guo <shawn.guo@linaro.org>,
	Stanimir Varbanov <svarbanov@mm-sol.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Xiaowei Song <songxiaowei@hisilicon.com>,
	Yue Wang <yue.wang@Amlogic.com>, Marc Zyngier <maz@kernel.org>,
	linux-amlogic@lists.infradead.org, linux-arm-kernel@axis.com,
	linux-arm-kernel@lists.infradead.org,
	linux-arm-msm@vger.kernel.org, linux-omap@vger.kernel.org,
	linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org
Subject: [PATCH v2 24/40] PCI: dwc: Ensure FAST_LINK_MODE is cleared
Date: Thu, 20 Aug 2020 21:54:04 -0600	[thread overview]
Message-ID: <20200821035420.380495-25-robh@kernel.org> (raw)
In-Reply-To: <20200821035420.380495-1-robh@kernel.org>

"Fast Link Mode" is a simulation environment speed up setting which should
never be set and the default is not set. However some Amlogic platforms
have it set (by firmware presumably). See commit 87dccf09323f ("PCI:
amlogic: meson: Don't use FAST_LINK_MODE to set up link") for more
information. Let's clear it in core DWC code so we can drop some vendor
specific code.

Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/pci/controller/dwc/pcie-designware.c | 5 ++++-
 drivers/pci/controller/dwc/pcie-designware.h | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 14ac87fa21a2..ed5dadcbcb45 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -560,6 +560,9 @@ void dw_pcie_setup(struct dw_pcie *pci)
 	dev_dbg(pci->dev, "iATU unroll: %s\n", pci->iatu_unroll_enabled ?
 		"enabled" : "disabled");
 
+	val = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
+	val &= ~PORT_LINK_FAST_LINK_MODE;
+	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
 
 	ret = of_property_read_u32(np, "num-lanes", &pci->num_lanes);
 	if (!pci->num_lanes) {
@@ -568,7 +571,7 @@ void dw_pcie_setup(struct dw_pcie *pci)
 	}
 
 	/* Set the number of lanes */
-	val = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
+	val &= ~PORT_LINK_FAST_LINK_MODE;
 	val &= ~PORT_LINK_MODE_MASK;
 	switch (pci->num_lanes) {
 	case 1:
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 43d3729101c3..40c3766df096 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -36,6 +36,7 @@
 
 #define PCIE_PORT_LINK_CONTROL		0x710
 #define PORT_LINK_DLL_LINK_EN		BIT(5)
+#define PORT_LINK_FAST_LINK_MODE	BIT(7)
 #define PORT_LINK_MODE_MASK		GENMASK(21, 16)
 #define PORT_LINK_MODE(n)		FIELD_PREP(PORT_LINK_MODE_MASK, n)
 #define PORT_LINK_MODE_1_LANES		PORT_LINK_MODE(0x1)
-- 
2.25.1

