On Fri, Nov 01, 2024 at 05:04:12PM GMT, Krishna chaitanya chundru wrote:
> If the vendor drivers can detect the Link up event using mechanisms
> such as Link up IRQ and can the driver can enumerate downstream devices
> instead of waiting here, then waiting for Link up during probe is not
> needed here, which optimizes the boot time.
>
> So skip waiting for link to be up if the driver supports 'linkup_irq'.
>
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-designware-host.c | 10 ++++++++--
> drivers/pci/controller/dwc/pcie-designware.h | 1 +
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 3e41865c7290..26418873ce14 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -530,8 +530,14 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
> goto err_remove_edma;
> }
>
> - /* Ignore errors, the link may come up later */
> - dw_pcie_wait_for_link(pci);
> + /*
> + * Note: The link up delay is skipped only when a link up IRQ is present.
> + * This flag should not be used to bypass the link up delay for arbitrary
> + * reasons.
Perhaps by improving the naming of the variable, you don't need 3 lines
of comment describing the conditional.
> + */
> + if (!pp->linkup_irq)
> + /* Ignore errors, the link may come up later */
Does this mean that we will be able to start handling these errors?
> + dw_pcie_wait_for_link(pci);
>
> bridge->sysdata = pp;
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 347ab74ac35a..539c6d106bb0 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -379,6 +379,7 @@ struct dw_pcie_rp {
> bool use_atu_msg;
> int msg_atu_index;
> struct resource *msg_res;
> + bool linkup_irq;
Please name this for what it is, rather than some property from which
some other decision should be derived. (And then you need a comment to
describe how people should interpret and use it)
Also, "linkup_irq" sound like an int carrying the interrupt number, not
a boolean.
Please call it "use_async_linkup", "use_linkup_irq" or something.
Regards,
Bjorn
> };
>
> struct dw_pcie_ep_ops {
>
> --
> 2.34.1
>
>
