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authorRichard Zhu <hongxing.zhu@nxp.com>2022-05-18 17:35:27 +0800
committerBjorn Helgaas <bhelgaas@google.com>2022-08-01 15:34:13 -0500
commit13f8f3d1e369f56dfaeea10a2238d56bc36c876c (patch)
tree7dcdb5726f3140c17495cee99397d023effeb314 /drivers/pci/controller/dwc
parent835a345b18b013cc03b0fc392394fbccd61d4efb (diff)
downloadlinux-13f8f3d1e369f56dfaeea10a2238d56bc36c876c.tar.bz2
PCI: imx6: Set PCIE_DBI_RO_WR_EN before writing DBI registers
The PCIE_DBI_RO_WR_EN bit should be set when write some DBI registers. To make sure that the DBI registers are writable, set the PCIE_DBI_RO_WR_EN properly when writing the DBI registers. Link: https://lore.kernel.org/r/1652866528-13220-1-git-send-email-hongxing.zhu@nxp.com Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/controller/dwc')
-rw-r--r--drivers/pci/controller/dwc/pci-imx6.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 81ab6ddb0d59..d11032388d23 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -830,10 +830,12 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
* started in Gen2 mode, there is a possibility the devices on the
* bus will not be detected at all. This happens with PCIe switches.
*/
+ dw_pcie_dbi_ro_wr_en(pci);
tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
tmp &= ~PCI_EXP_LNKCAP_SLS;
tmp |= PCI_EXP_LNKCAP_SLS_2_5GB;
dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
+ dw_pcie_dbi_ro_wr_dis(pci);
/* Start LTSSM. */
imx6_pcie_ltssm_enable(dev);
@@ -844,6 +846,7 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
if (pci->link_gen == 2) {
/* Allow Gen2 mode after the link is up. */
+ dw_pcie_dbi_ro_wr_en(pci);
tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
tmp &= ~PCI_EXP_LNKCAP_SLS;
tmp |= PCI_EXP_LNKCAP_SLS_5_0GB;
@@ -856,6 +859,7 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
tmp |= PORT_LOGIC_SPEED_CHANGE;
dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
+ dw_pcie_dbi_ro_wr_dis(pci);
if (imx6_pcie->drvdata->flags &
IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE) {