On Thu, Mar 31, 2022 at 12:53:45PM +0100, Dimitri John Ledkov wrote: > From: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> > > commit a382c757ec5ef83137a86125f43a4c43dc2ab50b upstream. > > The fu740 PCIe core does not probe any devices on the SiFive Unmatched > board without this fix (or having U-Boot explicitly start the PCIe via > either boot-script or user command). The fix is to start the link at > 2.5GT/s speeds and once the link is up then change the maximum speed back > to the default. > > The U-Boot driver claims to set the link-speed to 2.5GT/s to get the probe > to work (and U-Boot does print link up at 2.5GT/s) in the following code: > https://source.denx.de/u-boot/u-boot/-/blob/master/drivers/pci/pcie_dw_sifive.c?id=v2022.01#L271 > > Link: https://lore.kernel.org/r/20220318152430.526320-1-ben.dooks@xxxxxxxxxxxxxxx > Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> > Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@xxxxxxxxxxxxx> > --- > > Please apply this patch to v5.15+ stable trees which fixes PCIe on > the very popular SiFive Unmatched RISC-V board. > > drivers/pci/controller/dwc/pcie-fu740.c | 51 ++++++++++++++++++++++++- > 1 file changed, 50 insertions(+), 1 deletion(-) Now queued up, thanks. greg k-h
