PCI: mvebu: Update comment for PCI_EXP_LNKCAP register on emulated bridge

Reason for clearing this bit is because mvebu hw returns incorrectly this bit set to 1.

Link: https://lore.kernel.org/r/20220104153529.31647-10-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>

diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
index 1a03fb3..216da12 100644 (file)
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -546,8 +546,8 @@ mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
 
        case PCI_EXP_LNKCAP:
                /*
-                * PCIe requires the clock power management capability to be
-                * hard-wired to zero for downstream ports
+                * PCIe requires that the Clock Power Management capability bit
+                * is hard-wired to zero for downstream ports but HW returns 1.
                 */
                *value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCAP) &
                         ~PCI_EXP_LNKCAP_CLKPM;