@@ -528,14 +528,26 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci)
/* Check if the link is up or not */
for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
- if (dw_pcie_link_up(pci)) {
- dev_info(pci->dev, "Link up\n");
- return 0;
- }
+ if (dw_pcie_link_up(pci))
+ break;
+
usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
}
- dev_info(pci->dev, "Phy link never came up\n");
+ if (retries < LINK_WAIT_MAX_RETRIES) {
+ u32 offset, val;
+
+ offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+ val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);
+
+ dev_info(pci->dev, "PCIe Gen.%u x%u link up\n",
+ FIELD_GET(PCI_EXP_LNKSTA_CLS, val),
+ FIELD_GET(PCI_EXP_LNKSTA_NLW, val));
+
+ return 0;
+ }
+
+ dev_err(pci->dev, "Phy link never came up\n");
return -ETIMEDOUT;
}
Printing just "link up" isn't that much informative especially when it comes to working with the PCI Express bus. Even if the link is up, due to multiple reasons the bus performance can degrade to slower speeds or to narrower width than both Root Port and its partner is capable of. In that case it would be handy to know the link specifications as early as possible. So let's add a more verbose message to the busy-wait link-state method, which will contain the link speed generation and the PCIe bus width in case if the link up state is discovered. Otherwise an error will be printed to the system log. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> --- drivers/pci/controller/dwc/pcie-designware.c | 22 +++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-)