On Thu, Mar 18, 2021 at 12:02:44PM -0500, Bjorn Helgaas wrote:
> Drop the "downgraded" reporting for Downstream Ports. If there is a device
> below, we'll still complain at that end if it supports a faster/wider link
> than is available.
This makes sense, but I think we should still report if training has
gone horribly wrong. Maybe something like this ...
> +++ b/ls-caps.c
> @@ -758,13 +758,16 @@ static char *link_speed(int speed)
> }
> }
>
> -static char *link_compare(int sta, int cap)
> +static char *link_compare(int type, int sta, int cap)
> {
> + if ((type == PCI_EXP_TYPE_ROOT_PORT) || (type == PCI_EXP_TYPE_DOWNSTREAM) ||
> + (type == PCI_EXP_TYPE_PCIE_BRIDGE))
> + return "";
> if (sta < cap)
> - return "downgraded";
> + return " (downgraded)";
> if (sta > cap)
> - return "strange";
> - return "ok";
> + return " (strange)";
> + return " (ok)";
> }
{
if (sta > cap)
return " (overdriven)";
if (sta == cap)
return "";
if ((type == PCI_EXP_TYPE_ROOT_PORT) ||
((type == PCI_EXP_TYPE_DOWNSTREAM) ||
((type == PCI_EXP_TYPE_PCIE_BRIDGE))
return "";
return " (downgraded)";
}
(i don't know if the PCIe spec has a better word than overdriven for this
situation, but i don't like "strange". "invalid", maybe?)
The reason i say we should report it on the downstream port is that
we probably can't get to the config data on the upstream port/device,
so this may be our best chance to find out what's wrong.
