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| author |   Serge Semin <Sergey.Semin@baikalelectronics.ru> | 2022-06-24 17:39:33 +0300 |
|---|---|---|
| committer |   Bjorn Helgaas <bhelgaas@google.com> | 2022-08-01 15:01:25 -0500 |
| commit | 14c4ad125cf94ba226556dd5cffbd00c6482c6bd (patch) | |
| tree | a3e359ebf4f5dfabbee1f10fa11fa557f7e47c07 | |
| parent | PCI: dwc-plat: Drop dw_plat_pcie_of_match[] forward declaration (diff) | |
| download | linux-dev-14c4ad125cf94ba226556dd5cffbd00c6482c6bd.tar.xz linux-dev-14c4ad125cf94ba226556dd5cffbd00c6482c6bd.zip | |
PCI: dwc: Log link speed and width if it comes up
Printing just "link up" isn't very informative for PCI Express. Even if the
link is up, 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.
If the link comes up, log the link speed (PCIe generation) and width.
Link: https://lore.kernel.org/r/20220624143947.8991-2-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index ce01187947c9..e66d16a86168 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -524,20 +524,30 @@ void dw_pcie_disable_atu(struct dw_pcie *pci, int index, int dw_pcie_wait_for_link(struct dw_pcie *pci) { + u32 offset, val; int retries; /* 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) { + dev_err(pci->dev, "Phy link never came up\n"); + return -ETIMEDOUT; + } + + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); - return -ETIMEDOUT; + 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; } EXPORT_SYMBOL_GPL(dw_pcie_wait_for_link); |