On Tue, Feb 28, 2023 at 7:44 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > On Tue, Feb 28, 2023 at 08:53:50AM +0000, bugzilla-daemon@xxxxxxxxxx wrote: > > https://bugzilla.kernel.org/show_bug.cgi?id=217100 > > > > Summary: Bifurcation between pcie3x1 & pcie3x2 doesn't work in > > RK3568J. > > ... > > > Hello. > > > > First, I want to say that pcie3x1 crashes if started before pcie3x2 . Driver > > > pcie-designware.c > > > > in function > > > > > void dw_pcie_version_detect(struct dw_pcie *pci) > > > > tries to read parameter from dbi register (PCIE_VERSION_NUMBER) and fails on > > it. > > So I changed sequence of declaration PCIE in rk3568.dtsi: first - pcie3x2 next > > pcie3x1. Now Linux first starts pcie3x2, then successfully starts pcie3x1. > > > > But main problem is that bifurcation in phy driver > > > phy-rockchip-snps-pcie3.c > > > > doesn't work. I tried add next lines in function > > > > > static int rockchip_p3phy_probe(struct platform_device *pdev) > > > > right after block check > > > > > if (priv->num_lanes == -EINVAL) { > > > } > > > > > priv->num_lanes = 2; > > > priv->lanes[0] = 1; > > > priv->lanes[1] = 2 > > > > And driver writes during Linux boot process that bifurcation is enabled, but > > > > lspci > > > > does't show second device. > > > > Best regards, > > Anton. > > Thanks much for your report, Anton. People don't really pay attention > to the bugzilla, so I'm forwarding this to the mailing list and to > some folks who've worked on that driver in the past. > > MAINTAINERS doesn't list an entry for pcie-dw-rockchip.c; I'm not sure > if that's an oversight or if nobody cares enough to actually maintain > it. Good Afternoon, That bug report leaves a lot to be desired. Configuration of the phy must be completed correctly in the dts or the pci controller will hang and / or crash depending on kernel configuration parameters. Bifurcation is not automatic. At a minimum we need to know what device they are attempting this on as well as the full dts they attempted to use. A full kernel log would also be helpful. Very Respectfully, Peter Geis > > Bjorn
