[PATCH v9 4/5] PCI: controller: Validate max-link-speed

[Hans Zhang <18255117159@163.com>]

Add validation for the "max-link-speed" DT property in three more
drivers, using the pcie_get_link_speed() helper.

- brcmstb: If the value is missing or invalid, fall back to no
  limitation (pcie->gen = 0).  Fix the previous incorrect logic.
- mediatek-gen3: If the value is missing or invalid, use the maximum
  speed supported by the controller.
- rzg3s-host: If the value is missing or invalid, fall back to Gen2.

This ensures that all users of of_pci_get_max_link_speed() are ready
for the removal of the central range check.

Signed-off-by: Hans Zhang <18255117159@163.com>
---
 drivers/pci/controller/pcie-brcmstb.c       | 5 +++--
 drivers/pci/controller/pcie-mediatek-gen3.c | 2 +-
 drivers/pci/controller/pcie-rzg3s-host.c    | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 062f55690012..714bcab97b60 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -1442,7 +1442,7 @@ static int brcm_pcie_start_link(struct brcm_pcie *pcie)
 	cls = FIELD_GET(PCI_EXP_LNKSTA_CLS, lnksta);
 	nlw = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
 	dev_info(dev, "link up, %s x%u %s\n",
-		 pci_speed_string(pcie_link_speed[cls]), nlw,
+		 pci_speed_string(pcie_get_link_speed(cls)), nlw,
 		 ssc_good ? "(SSC)" : "(!SSC)");
 
 	return 0;
@@ -2072,7 +2072,8 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(pcie->clk);
 
 	ret = of_pci_get_max_link_speed(np);
-	pcie->gen = (ret < 0) ? 0 : ret;
+	if (pcie_get_link_speed(ret) == PCI_SPEED_UNKNOWN)
+		pcie->gen = 0;
 
 	pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
 
diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index 75ddb8bee168..3b903ef7d3cf 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -1150,7 +1150,7 @@ static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
 		return err;
 
 	err = of_pci_get_max_link_speed(pcie->dev->of_node);
-	if (err) {
+	if (pcie_get_link_speed(err) != PCI_SPEED_UNKNOWN) {
 		/* Get the maximum speed supported by the controller */
 		max_speed = mtk_pcie_get_controller_max_link_speed(pcie);
 
diff --git a/drivers/pci/controller/pcie-rzg3s-host.c b/drivers/pci/controller/pcie-rzg3s-host.c
index 2809112e6317..00a11f986117 100644
--- a/drivers/pci/controller/pcie-rzg3s-host.c
+++ b/drivers/pci/controller/pcie-rzg3s-host.c
@@ -966,7 +966,7 @@ static int rzg3s_pcie_set_max_link_speed(struct rzg3s_pcie_host *host)
 	ls = readw_relaxed(host->pcie + pcie_cap + PCI_EXP_LNKSTA);
 	cs2 = readl_relaxed(host->axi + RZG3S_PCI_PCSTAT2);
 
-	switch (pcie_link_speed[host->max_link_speed]) {
+	switch (pcie_get_link_speed(host->max_link_speed)) {
 	case PCIE_SPEED_5_0GT:
 		max_supported_link_speeds = GENMASK(PCI_EXP_LNKSTA_CLS_5_0GB - 1, 0);
 		link_speed = PCI_EXP_LNKCTL2_TLS_5_0GT;
-- 
2.34.1