[PATCH v2] PCI: brcmstb: Assign pcie->gen from of_pci_get_max_link_speed()

[Florian Fainelli <florian.fainelli@broadcom.com>]

After commit 03f920936977 ("PCI: controller: Validate max-link-speed"),
pcie->gen stopped being assigned and as a result the established PCIe
link would stop supporting Gen3 speeds on 2712 since pcie->gen is used
to populate LnkCntl2 and LnkCap in brcm_pcie_set_gen().

Whether the 'max-link-speed' property is not specified, or it exceeds
Gen3, resort to the HW defaults.

Link: https://github.com/raspberrypi/linux/issues/7343
Reported-by: Dom Cobley <popcornmix@gmail.com>
Reported-by: Phil Elwell <phil@raspberrypi.com>
Fixes: 03f920936977 ("PCI: controller: Validate max-link-speed")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Change-Id: Ic5431469dd7a6c8b391f84f27119dad876256880
---
Changes in v2:

- utilize of_pci_get_max_link_speed() directly
- also validate against exceeding Gen3

 drivers/pci/controller/pcie-brcmstb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 714bcab97b60..08a0e7091ced 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -2072,8 +2072,10 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(pcie->clk);
 
 	ret = of_pci_get_max_link_speed(np);
-	if (pcie_get_link_speed(ret) == PCI_SPEED_UNKNOWN)
+	if (ret < 0 || ret > 3)
 		pcie->gen = 0;
+	else
+		pcie->gen = ret;
 
 	pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
 
-- 
2.34.1