5.15-stable review patch. If anyone has any objections, please let me know.
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From: Jim Quinlan james.quinlan@broadcom.com
[ Upstream commit 0c97321e11e0e9e18546f828492758f6aaecec59 ]
The driver has been mistakenly writing to a read-only (RO) configuration space register (PCI_EXP_LNKCAP) to change the PCIe link capability.
Although harmless in this case, the proper write destination is an internal register that is reflected by PCI_EXP_LNKCAP.
Thus, fix the brcm_pcie_set_gen() function to correctly update the link capability.
Fixes: c0452137034b ("PCI: brcmstb: Add Broadcom STB PCIe host controller driver") Signed-off-by: Jim Quinlan james.quinlan@broadcom.com Reviewed-by: Florian Fainelli florian.fainelli@broadcom.com Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Link: https://lore.kernel.org/r/20250214173944.47506-3-james.quinlan@broadcom.com [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/pcie-brcmstb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index cc30215f5a433..c3c1d700f519a 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -410,10 +410,10 @@ static int brcm_pcie_set_ssc(struct brcm_pcie *pcie) static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen) { u16 lnkctl2 = readw(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2); - u32 lnkcap = readl(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP); + u32 lnkcap = readl(pcie->base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen; - writel(lnkcap, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP); + writel(lnkcap, pcie->base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
lnkctl2 = (lnkctl2 & ~0xf) | gen; writew(lnkctl2, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);