From: Marc Zyngier maz@kernel.org
[ Upstream commit 87dccf09323fc363bd0d072fcc12b96622ab8c69 ]
The vim3l board does not work with a standard PCIe switch (ASM1184e), spitting all kind of errors - hinting at HW misconfiguration (no link, port enumeration issues, etc).
According to the the Synopsys DWC PCIe Reference Manual, in the section dedicated to the PLCR register, bit 7 is described (FAST_LINK_MODE) as:
"Sets all internal timers to fast mode for simulation purposes."
it is sound to set this bit from a simulation perspective, but on actual silicon, which expects timers to have a nominal value, it is not.
Make sure the FAST_LINK_MODE bit is cleared when configuring the RC to solve this problem.
Link: https://lore.kernel.org/r/20200429164230.309922-1-maz@kernel.org Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver") Signed-off-by: Marc Zyngier maz@kernel.org [lorenzo.pieralisi@arm.com: commit log] Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Reviewed-by: Neil Armstrong narmstrong@baylibre.com Acked-by: Rob Herring robh@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/dwc/pci-meson.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c index b927a92e3463..8c9f88704874 100644 --- a/drivers/pci/controller/dwc/pci-meson.c +++ b/drivers/pci/controller/dwc/pci-meson.c @@ -301,11 +301,11 @@ static void meson_pcie_init_dw(struct meson_pcie *mp) meson_cfg_writel(mp, val, PCIE_CFG0);
val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF); - val &= ~LINK_CAPABLE_MASK; + val &= ~(LINK_CAPABLE_MASK | FAST_LINK_MODE); meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF); - val |= LINK_CAPABLE_X1 | FAST_LINK_MODE; + val |= LINK_CAPABLE_X1; meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);