[PATCH 5.10 345/545] PCI: tegra194: Fix Root Port interrupt handling

Greg Kroah-Hartman
2022-08-19T16:32:41Z

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 845f1e1de3ab..bcbd600116d7 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -370,15 +370,14 @@ static irqreturn_t tegra_pcie_rp_irq_handler(int irq, void *arg)
struct tegra_pcie_dw *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;
@@ -394,15 +393,15 @@ 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);
@@ -414,25 +413,24 @@ 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;
--
2.35.1