From: Vidya Sagar vidyas@nvidia.com
[ Upstream commit 6646e99bcec627e866bc84365af37942c72b4b76 ]
As part of Root Port interrupt handling, level-0 register is read first and based on the bits set in that, corresponding level-1 registers are read for further interrupt processing. Since both these values are currently read into the same 'val' variable, checking level-0 bits the second time around is happening on the 'val' variable value of level-1 register contents instead of freshly reading the level-0 value again.
Fix by using different variables to store level-0 and level-1 registers contents.
Link: https://lore.kernel.org/r/20220721142052.25971-11-vidyas@nvidia.com Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support") Signed-off-by: Vidya Sagar vidyas@nvidia.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/dwc/pcie-tegra194.c | 46 +++++++++++----------- 1 file changed, 22 insertions(+), 24 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index d992371a36e6..0bab700086f9 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -350,15 +350,14 @@ static irqreturn_t tegra_pcie_rp_irq_handler(int irq, void *arg) struct tegra194_pcie *pcie = arg; struct dw_pcie *pci = &pcie->pci; struct pcie_port *pp = &pci->pp; - u32 val, tmp; + u32 val, status_l0, status_l1; u16 val_w;
- val = appl_readl(pcie, APPL_INTR_STATUS_L0); - if (val & APPL_INTR_STATUS_L0_LINK_STATE_INT) { - val = appl_readl(pcie, APPL_INTR_STATUS_L1_0_0); - if (val & APPL_INTR_STATUS_L1_0_0_LINK_REQ_RST_NOT_CHGED) { - appl_writel(pcie, val, APPL_INTR_STATUS_L1_0_0); - + status_l0 = appl_readl(pcie, APPL_INTR_STATUS_L0); + if (status_l0 & APPL_INTR_STATUS_L0_LINK_STATE_INT) { + status_l1 = appl_readl(pcie, APPL_INTR_STATUS_L1_0_0); + appl_writel(pcie, status_l1, APPL_INTR_STATUS_L1_0_0); + if (status_l1 & APPL_INTR_STATUS_L1_0_0_LINK_REQ_RST_NOT_CHGED) { /* SBR & Surprise Link Down WAR */ val = appl_readl(pcie, APPL_CAR_RESET_OVRD); val &= ~APPL_CAR_RESET_OVRD_CYA_OVERRIDE_CORE_RST_N; @@ -374,15 +373,15 @@ static irqreturn_t tegra_pcie_rp_irq_handler(int irq, void *arg) } }
- if (val & APPL_INTR_STATUS_L0_INT_INT) { - val = appl_readl(pcie, APPL_INTR_STATUS_L1_8_0); - if (val & APPL_INTR_STATUS_L1_8_0_AUTO_BW_INT_STS) { + if (status_l0 & APPL_INTR_STATUS_L0_INT_INT) { + status_l1 = appl_readl(pcie, APPL_INTR_STATUS_L1_8_0); + if (status_l1 & APPL_INTR_STATUS_L1_8_0_AUTO_BW_INT_STS) { appl_writel(pcie, APPL_INTR_STATUS_L1_8_0_AUTO_BW_INT_STS, APPL_INTR_STATUS_L1_8_0); apply_bad_link_workaround(pp); } - if (val & APPL_INTR_STATUS_L1_8_0_BW_MGT_INT_STS) { + if (status_l1 & APPL_INTR_STATUS_L1_8_0_BW_MGT_INT_STS) { appl_writel(pcie, APPL_INTR_STATUS_L1_8_0_BW_MGT_INT_STS, APPL_INTR_STATUS_L1_8_0); @@ -394,25 +393,24 @@ static irqreturn_t tegra_pcie_rp_irq_handler(int irq, void *arg) } }
- val = appl_readl(pcie, APPL_INTR_STATUS_L0); - if (val & APPL_INTR_STATUS_L0_CDM_REG_CHK_INT) { - val = appl_readl(pcie, APPL_INTR_STATUS_L1_18); - tmp = dw_pcie_readl_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS); - if (val & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMPLT) { + if (status_l0 & APPL_INTR_STATUS_L0_CDM_REG_CHK_INT) { + status_l1 = appl_readl(pcie, APPL_INTR_STATUS_L1_18); + val = dw_pcie_readl_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS); + if (status_l1 & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMPLT) { dev_info(pci->dev, "CDM check complete\n"); - tmp |= PCIE_PL_CHK_REG_CHK_REG_COMPLETE; + val |= PCIE_PL_CHK_REG_CHK_REG_COMPLETE; } - if (val & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMP_ERR) { + if (status_l1 & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMP_ERR) { dev_err(pci->dev, "CDM comparison mismatch\n"); - tmp |= PCIE_PL_CHK_REG_CHK_REG_COMPARISON_ERROR; + val |= PCIE_PL_CHK_REG_CHK_REG_COMPARISON_ERROR; } - if (val & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_LOGIC_ERR) { + if (status_l1 & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_LOGIC_ERR) { dev_err(pci->dev, "CDM Logic error\n"); - tmp |= PCIE_PL_CHK_REG_CHK_REG_LOGIC_ERROR; + val |= PCIE_PL_CHK_REG_CHK_REG_LOGIC_ERROR; } - dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, tmp); - tmp = dw_pcie_readl_dbi(pci, PCIE_PL_CHK_REG_ERR_ADDR); - dev_err(pci->dev, "CDM Error Address Offset = 0x%08X\n", tmp); + dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, val); + val = dw_pcie_readl_dbi(pci, PCIE_PL_CHK_REG_ERR_ADDR); + dev_err(pci->dev, "CDM Error Address Offset = 0x%08X\n", val); }
return IRQ_HANDLED;