On Fri, Nov 08, 2019 at 04:30:27PM +0900, Kunihiko Hayashi wrote: > > However, If I understand correctly, doesn't your solution only work some > > of the time? What happens if you boot both machines at the same time, > > and PERST# isn't asserted prior to the kernel booting? > > I think it contains an annoying problem. > > If PERST# isn't toggled prior to the kernel booting, PERST# remains asserted > and the RC driver can't access PCI bus. > > As a result, this patch works and deasserts PERST# (and EP configuration will > be lost). So boot sequence needs to include deasserting PERST#. I am sorry but I have lost you. Can you explain to us why checking that PERST# is deasserted guarantees you that: - The EP has bootstrapped - It is safe not to toggle it again (and also skip uniphier_pcie_ltssm_enable()) Please provide details of the HW configuration so that we understand what's actually supposed to happen and why this patch fixes the issue you are facing. Thanks, Lorenzo
