[PATCH 6.4 488/800] PCI: qcom: Disable write access to read only registers for IP v2.9.0

Greg Kroah-Hartman
2023-07-16T20:15:46Z

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

[ Upstream commit 200b8f85f2021362adcc8efb575652a2aa44c099 ]

In the post init sequence of v2.9.0, write access to read only registers
are not disabled after updating the registers. Fix it by disabling the
access after register update.

While at it, let's also add a newline after existing dw_pcie_dbi_ro_wr_en()
guard function to align with rest of the driver.

Link: https://lore.kernel.org/r/20230619150408.8468-4-manivannan.sadhasivam@linaro.org
Fixes: 0cf7c2efe8ac ("PCI: qcom: Add IPQ60xx support")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/controller/dwc/pcie-qcom.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 8185db887c9db..2783e9c3ef1ba 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1134,6 +1134,7 @@ static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
writel(0, pcie->parf + PARF_Q2A_FLUSH);

dw_pcie_dbi_ro_wr_en(pci);
+
writel(PCIE_CAP_SLOT_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);

val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
@@ -1143,6 +1144,8 @@ static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
PCI_EXP_DEVCTL2);

+ dw_pcie_dbi_ro_wr_dis(pci);
+
for (i = 0; i < 256; i++)
writel(0, pcie->parf + PARF_BDF_TO_SID_TABLE_N + (4 * i));

--
2.39.2