Thinh Nguyen [off-list ref] 于2020年8月4日周二 上午8:46写道：

Hi Rob,

Tejas Joglekar wrote:

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Hello Rob,
On 7/21/2020 10:27 PM, Tejas Joglekar wrote:

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Hello,

On 7/21/2020 3:17 PM, Felipe Balbi wrote:

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Tejas Joglekar [off-list ref] writes:

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Hi Rob,

On 7/6/2020 12:13 PM, Felipe Balbi wrote:

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Hi,

Tejas Joglekar [off-list ref] writes:

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@@ -95,6 +95,10 @@ int dwc3_host_init(struct dwc3 *dwc)
        if (dwc->usb2_lpm_disable)
                props[prop_idx++] = PROPERTY_ENTRY_BOOL("usb2-lpm-disable");

+       if (dwc->sgl_trb_cache_size_quirk)
+               props[prop_idx++] =
+                       PROPERTY_ENTRY_BOOL("sgl-trb-cache-size-quirk");
+
        /**
         * WORKAROUND: dwc3 revisions <=3.00a have a limitation
         * where Port Disable command doesn't work.

Does this implementation looks good to you? Rob has some concerned over the DT entries,
you suggested using compatible string with this quirk addition.
Can you please brief about how you would like to have this quirk implemented?
I can send the updated patch. My patch series is pending for merge just because of the
DT and quirk issue. Can you please help?

Yeah, you need to get into an agreement with Rob :-) I don't mind having
extra DT flags for things which can't be detected in runtime, Rob
disagrees.

The compatible string is not suitable option as it does not work with platform drivers
with PCI based system. Also Synopsys controllers IP version register is not visible to xhci
driver and hence we don't have separate compatible string for each Synopsys version on the
xhci driver side.
Due to which I depend on DT flag addition for the quirk. Can we add these DT flags and quirk?

As I said, I'm well aware of the situation regarding usage of compatible
strings and the fact that dwc3 must work on PCI and non-PCI systems (I
wrote the thing as it is after all). The person blocking new quirk flags
is Rob, not me. You need to convince Rob that this is the way to go.

@Felipe: Sorry for confusion if any, previous mail was intended for Rob asking about his approval.

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Rob, ball's in your court. Sorry.>

@Rob: As I and Felipe have mentioned before, it is very much necessary to have quirk flags
for the current changes as compatible string would not be a solution for PCI and non-PCI
systems. Can you please approve this change ? If you have any concern about naming or any
other thing, please let us know.

Can you please comment?

Thanks & Regards,
Tejas Joglekar

Can you help provide pointers and changes that Tejas can make to help
bring this issue to conclusion?

We really need a direction to handle growing dwc3 quirks/flags as dwc3
is widly used,
I have a patchset also pending there after tried both property[1] and
platform data[2].

[1] https://www.spinics.net/lists/linux-usb/msg196055.html
[2] https://www.spinics.net/lists/arm-kernel/msg824995.html

thanks
Li Jun

Thanks,
Thinh