Re: [PATCH] PCI: dw-rockchip: Skip waiting for link up

Niklas Cassel
2025-01-13T21:15:56Z

On 13 January 2025 20:27:20 CET, Bjorn Helgaas <helgaas@kernel.org> wrote:
>On Mon, Jan 13, 2025 at 11:59:34AM +0100, Niklas Cassel wrote:
>> The Root Complex specific device tree binding for pcie-dw-rockchip has the
>> 'sys' interrupt marked as required.
>>
>> The driver requests the 'sys' IRQ unconditionally, and errors out if not
>> provided.
>>
>> Thus, we can unconditionally set use_linkup_irq before calling
>> dw_pcie_host_init().
>>
>> This will skip the wait for link up (since the bus will be enumerated once
>> the link up IRQ is triggered), which reduces the bootup time.
>>
>> Signed-off-by: Niklas Cassel <cassel@kernel.org>
>
>Thanks! I was just reviewing the addition of your dll_link_up IRQ
>handler, and was about to ask whether you wanted to set use_linkup_irq
>to avoid the wait, but here's the patch already :)

:)

>
>I think I'll sort out the branches so the dll_link_up IRQ handler,
>this patch, and the corresponding qcom change go on the same branch as
>Krishna's patch to skip waiting if pp->use_linkup_irq.

That sounds like a good idea.

Thank you!

Kind regards,
Niklas

>
>> ---
>> drivers/pci/controller/dwc/pcie-dw-rockchip.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
>> index 1170e1107508bd793b610949b0afe98516c177a4..62034affb95fbb965aad3cebc613a83e31c90aee 100644
>> --- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
>> +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
>> @@ -435,6 +435,7 @@ static int rockchip_pcie_configure_rc(struct rockchip_pcie *rockchip)
>>
>> pp = &rockchip->pci.pp;
>> pp->ops = &rockchip_pcie_host_ops;
>> + pp->use_linkup_irq = true;
>>
>> return dw_pcie_host_init(pp);
>> }
>>
>> ---
>> base-commit: 2adda4102931b152f35d054055497631ed97fe73
>> change-id: 20250113-rockchip-no-wait-403ffbc42313
>>
>> Best regards,
>> --
>> Niklas Cassel <cassel@kernel.org>
>>