The subject lines are not quite accurate. The warning does nothing to
*prevent* invalid values; it only warns about them.
And it should say what *kind* of values we're talking about.
Maybe:
PCI: dwc: Warn about invalid 'max-link-speed' from DT
On Mon, Nov 07, 2022 at 11:31:07PM +0800, JunDong Song wrote:
> of_pci_get_max_link_speed() may return a negative value,
> causing the controller to not set the speed correctly.
> Add a warning in case the driver engineer misses it.
Rewrap this to fill 75 columns.
I would probably squash these into a single patch since they're
doing exactly the same thing to the host and endpoint cases.
> Signed-off-by: JunDong Song <jundongsong1@xxxxxxxxx>
> ---
>
> When I use the pcie dwc driver, the controller speed is abnormal,
> but it has not been detected because of the @max-link-speed error,
> so I think I need to return an error or warning here.
>
> Thanks.
>
> drivers/pci/controller/dwc/pcie-designware-ep.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 83ddb1902..573342601 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -739,8 +739,11 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> return -ENOMEM;
> ep->outbound_addr = addr;
>
> - if (pci->link_gen < 1)
> + if (pci->link_gen < 1) {
> pci->link_gen = of_pci_get_max_link_speed(np);
> + if (unlikely(pci->link_gen < 0))
Using "unlikely" here is unnecessary since this is not a performance
path, and it's a distraction.
> + dev_warn(dev, "Failed to get max link speed\n");
> + }
>
> epc = devm_pci_epc_create(dev, &epc_ops);
> if (IS_ERR(epc)) {
> --
> 2.25.1
>
