On 24/02/2023 23:09, Sajid Dalvi wrote: > On Fri, Feb 24, 2023 at 3:29 PM Krzysztof Kozlowski > <krzysztof.kozlowski@xxxxxxxxxx> wrote: >> >> On 24/02/2023 22:27, Sajid Dalvi wrote: >>> On Fri, Feb 24, 2023 at 2:40 PM Krzysztof Kozlowski >>> <krzysztof.kozlowski@xxxxxxxxxx> wrote: >>>> >>>> On 24/02/2023 20:57, Sajid Dalvi wrote: >>>>> When the Root Complex is probed, the default behavior is to spin in a loop >>>>> waiting for the link to come up. In some systems the link is not brought up >>>>> during probe, but later in the context of an end-point turning on. >>>>> This property will allow the loop to be skipped. >>>>> >>>>> Signed-off-by: Sajid Dalvi <sdalvi@xxxxxxxxxx> >>>>> --- >>>> >>>> Thank you for your patch. There is something to discuss/improve. >>>> >>>>> Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml | 8 ++++++++ >>>>> 1 file changed, 8 insertions(+) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml b/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml >>>>> index 1a83f0f65f19..0b8950a73b7e 100644 >>>>> --- a/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml >>>>> +++ b/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml >>>>> @@ -197,6 +197,14 @@ properties: >>>>> - contains: >>>>> const: msi >>>>> >>>>> + snps,skip-wait-link-up: >>>>> + $ref: /schemas/types.yaml#/definitions/flag >>>>> + description: >>>>> + When the Root Complex is probed, the default behavior is to spin in a >>>>> + loop waiting for the link to come up. In some systems the link is not >>>>> + brought up during probe, but later in the context of an end-point turning >>>>> + on. This property will allow the loop to be skipped. >>>> >>>> I fail to see how probe behavior is related to properties of hardware. >>>> You describe OS behavior, not hardware. This does not look like >>>> belonging to DT. >>>> >>>> >>>> Best regards, >>>> Krzysztof >>> >>> Thanks for your response Krzysztof. >>> The hardware configuration of the system determines whether an >>> endpoint device is available during host init. If it isn't available >>> on a particular and dedicated pcie interface, we should skip waiting >>> for the link to be up. For other interfaces, possibly even on the same >>> system, where a device is present or maybe present we should wait for >>> the link to come up. >> >> Keep discussions public. >> >> Your commit and property description mentions probe, which is nothing >> related to hardware. Why the device would not be available during host >> init (I understand we do not talk about hotplug as it is already >> supported by Linux) in a way it is hardware property, not OS? >> >> Best regards, >> Krzysztof >> > > + everyone else I mistakenly didn't reply to earlier > > If I understand you correctly, the usage of probe is misleading > because it doesn't have anything to do with the hardware. > So your recommendation is to replace probe with device init, in the > description of the property and the commit message? No, I asked there a question for which we need answer. device init is also OS task... You need to explain why this is a property of hardware, not OS behavior. Best regards, Krzysztof
