PCI: brcmstb: Use internal register to change link capability

[ 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: c045213703 ("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>
This commit is contained in:
Jim Quinlan
2025-02-14 12:39:30 -05:00
committed by Greg Kroah-Hartman
parent 9ce67aa3c6
commit 5bb237a1f6

View File

@@ -383,10 +383,10 @@ 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);