PCI: qcom: Disable write access to read only registers for IP v2.9.0

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/[email protected]
Fixes: 0cf7c2e ("PCI: qcom: Add IPQ60xx support")
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>

Author: Mani-Sadhasivam

drivers/pci/controller/dwc/pcie-qcom.c

@@ -1136,6 +1136,7 @@ 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);
@@ -1145,6 +1146,8 @@ 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));