> -----Original Message----- > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> > Sent: 2022年7月12日 6:17 > To: Hongxing Zhu <hongxing.zhu@xxxxxxx> > Cc: l.stach@xxxxxxxxxxxxxx; bhelgaas@xxxxxxxxxx; > lorenzo.pieralisi@xxxxxxx; festevam@xxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > kernel@xxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx> > Subject: Re: [RFC 1/2] PCI: imx6: Make sure the DBI register can be changed > > Hi Richard, > > On Wed, May 18, 2022 at 05:35:27PM +0800, Richard Zhu wrote: > > 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 touch the DBI registers. > > > > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> > > --- > > drivers/pci/controller/dwc/pci-imx6.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > > b/drivers/pci/controller/dwc/pci-imx6.c > > index 6619e3caffe2..30641d2dda14 100644 > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > @@ -797,10 +797,12 @@ 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); > > What's the status of this patch? I don't see this change included in your v14 > series [1]. That series has a lot of imx6 updates, so I would have thought > you'd include this change in it. Or maybe this change turned out not to be > needed? Hi Bjorn: Thanks for your kindly help. The v14 series[1] had been reviewing for a quite time. I'm afraid that this series might miss the L5.20 merge window if I add new patch into it from time to time. If you don't think so, I can merge the first one, and re-issue the v15 a moment later. > > What about the 2/2 patch? i.MX8MP PCIe supports the PCIe GEN3 speed, the second patch is used to extend the link speed support capability, and prepared for i.MX8MP PCIe support. I assumed that these two patches can be contained in i.MX8MP PCIe support patch-set before. > > They're both marked "RFC" which is sometimes a hint that the author isn't > really committed to the patch, so sometimes they don't get the attention they > deserve. > I see. Would remove the "RFC" when issue the patch next time. Thanks. Best Regards Richard Zhu > Bjorn > > [1] > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.ker > nel.org%2Fr%2F1656645935-1370-1-git-send-email-hongxing.zhu%40nxp.com > &data=05%7C01%7Chongxing.zhu%40nxp.com%7C62e9d070313048589 > 90308da638b18b4%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C > 637931746310188774%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAw > MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C% > 7C&sdata=Oz2Zgdch0gI2Qd66AiM5iWmp23uwn1SkH07gDAQhGQY%3D > &reserved=0 > > > 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); > > @@ -809,6 +811,7 @@ 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; > > @@ -821,6 +824,7 @@ 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) { > > -- > > 2.25.1 > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > > https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists > > .infradead.org%2Fmailman%2Flistinfo%2Flinux-arm-kernel&data=05%7 > C0 > > > 1%7Chongxing.zhu%40nxp.com%7C62e9d07031304858990308da638b18b4% > 7C686ea1 > > > d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637931746310188774%7CUnk > nown%7CTW > > > FpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXV > CI6 > > > Mn0%3D%7C3000%7C%7C%7C&sdata=mG6ix8VqqWocpp62GIWxgQOpE > xSCMDJivto%2 > > BmqgOZHs%3D&reserved=0
