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

Rob Herring
2020-08-21T03:56:07Z

"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