LinuxLists.cc - [PATCH v7 0/4] ADD interconnect support for Qualcomm DWC3 driver

2020-05-14 11:31:42

by Felipe Balbi

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Subject: Re: [PATCH v7 2/4] usb: dwc3: qcom: Add interconnect support in dwc3 driver

Hi,

Sandeep Maheswaram <[email protected]> writes:
> +static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
> +{
> + struct device *dev = qcom->dev;
> + int ret;
> +
> + if (!device_is_bound(&qcom->dwc3->dev))
> + return -EPROBE_DEFER;

this breaks allmodconfig. I'm dropping this series from my queue for
this merge window.

--
balbi

Attachments:

signature.asc (847.00 B)

2020-05-14 11:34:23

Hi,

Georgi Djakov <[email protected]> writes:
> On 5/14/20 20:13, Matthias Kaehlcke wrote:
>> On Thu, May 14, 2020 at 02:30:28PM +0300, Felipe Balbi wrote:
>>> Felipe Balbi <[email protected]> writes:
>>>
>>>> Hi,
>>>>
>>>> Sandeep Maheswaram <[email protected]> writes:
>>>>> +static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
>>>>> +{
>>>>> + struct device *dev = qcom->dev;
>>>>> + int ret;
>>>>> +
>>>>> + if (!device_is_bound(&qcom->dwc3->dev))
>>>>> + return -EPROBE_DEFER;
>>>>
>>>> this breaks allmodconfig. I'm dropping this series from my queue for
>>>> this merge window.
>>>
>>> Sorry, I meant this patch ;-)
>>
>> I guess that's due to INTERCONNECT being a module. There is currently a
>
> I believe it's because of this:
> ERROR: modpost: "device_is_bound" [drivers/usb/dwc3/dwc3-qcom.ko] undefined!
>
>> discussion about this with Viresh and Georgi in response to another
>> automated build failure. Viresh suggests changing CONFIG_INTERCONNECT
>> from tristate to bool, which seems sensible to me given that interconnect
>> is a core subsystem.
>
> The problem you are talking about would arise when INTERCONNECT=m and
> USB_DWC3_QCOM=y and it definitely exists here and could be triggered with
> randconfig build. So i suggest to squash also the diff below.
>
> Thanks,
> Georgi
>
> ---8<---
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 206caa0ea1c6..6661788b1a76 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -129,6 +129,7 @@ config USB_DWC3_QCOM
> tristate "Qualcomm Platform"
> depends on ARCH_QCOM || COMPILE_TEST
> depends on EXTCON || !EXTCON
> + depends on INTERCONNECT || !INTERCONNECT

I would prefer to see a patch adding EXPORT_SYMBOL_GPL() to device_is_bound()

--
balbi

Attachments:

signature.asc (847.00 B)

2020-05-15 06:14:24

by Georgi Djakov

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Subject: Re: [PATCH v7 2/4] usb: dwc3: qcom: Add interconnect support in dwc3 driver

Hi,

On 5/15/20 08:54, Felipe Balbi wrote:
>
> Hi,
>
> Georgi Djakov <[email protected]> writes:
>> On 5/14/20 20:13, Matthias Kaehlcke wrote:
>>> On Thu, May 14, 2020 at 02:30:28PM +0300, Felipe Balbi wrote:
>>>> Felipe Balbi <[email protected]> writes:
>>>>
>>>>> Hi,
>>>>>
>>>>> Sandeep Maheswaram <[email protected]> writes:
>>>>>> +static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
>>>>>> +{
>>>>>> + struct device *dev = qcom->dev;
>>>>>> + int ret;
>>>>>> +
>>>>>> + if (!device_is_bound(&qcom->dwc3->dev))
>>>>>> + return -EPROBE_DEFER;
>>>>>
>>>>> this breaks allmodconfig. I'm dropping this series from my queue for
>>>>> this merge window.
>>>>
>>>> Sorry, I meant this patch ;-)
>>>
>>> I guess that's due to INTERCONNECT being a module. There is currently a
>>
>> I believe it's because of this:
>> ERROR: modpost: "device_is_bound" [drivers/usb/dwc3/dwc3-qcom.ko] undefined!
>>
>>> discussion about this with Viresh and Georgi in response to another
>>> automated build failure. Viresh suggests changing CONFIG_INTERCONNECT
>>> from tristate to bool, which seems sensible to me given that interconnect
>>> is a core subsystem.
>>
>> The problem you are talking about would arise when INTERCONNECT=m and
>> USB_DWC3_QCOM=y and it definitely exists here and could be triggered with
>> randconfig build. So i suggest to squash also the diff below.
>>
>> Thanks,
>> Georgi
>>
>> ---8<---
>> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>> index 206caa0ea1c6..6661788b1a76 100644
>> --- a/drivers/usb/dwc3/Kconfig
>> +++ b/drivers/usb/dwc3/Kconfig
>> @@ -129,6 +129,7 @@ config USB_DWC3_QCOM
>> tristate "Qualcomm Platform"
>> depends on ARCH_QCOM || COMPILE_TEST
>> depends on EXTCON || !EXTCON
>> + depends on INTERCONNECT || !INTERCONNECT
>
> I would prefer to see a patch adding EXPORT_SYMBOL_GPL() to device_is_bound()

Agree, but just to clarify, that these are two separate issues that need to
be fixed. The device_is_bound() is the first one and USB_DWC3_QCOM=y combined
with INTERCONNECT=m is the second one.

Thanks,
Georgi

2020-05-15 06:31:45

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Subject: Re: [PATCH v7 2/4] usb: dwc3: qcom: Add interconnect support in dwc3 driver

On 7/1/2020 4:12 AM, Matthias Kaehlcke wrote:
> On Tue, Jun 16, 2020 at 01:38:49PM -0700, Matthias Kaehlcke wrote:
>> On Tue, Jun 16, 2020 at 10:22:47AM +0530, Sandeep Maheswaram (Temp) wrote:
>>> On 6/16/2020 1:12 AM, Matthias Kaehlcke wrote:
>>>> On Thu, Jun 04, 2020 at 04:16:31AM -0700, Stephen Boyd wrote:
>>>>> Quoting Sandeep Maheswaram (Temp) (2020-06-04 02:43:09)
>>>>>> On 6/3/2020 11:06 PM, Stephen Boyd wrote:
>>>>>>> Quoting Sandeep Maheswaram (2020-03-31 22:15:43)
>>>>>>>> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
>>>>>>>> index 1dfd024..d33ae86 100644
>>>>>>>> --- a/drivers/usb/dwc3/dwc3-qcom.c
>>>>>>>> +++ b/drivers/usb/dwc3/dwc3-qcom.c
>>>>>>>> @@ -285,6 +307,101 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
>>>>>>>> return 0;
>>>>>>>> }
>>>>>>>> +
>>>>>>>> +/**
>>>>>>>> + * dwc3_qcom_interconnect_init() - Get interconnect path handles
>>>>>>>> + * @qcom: Pointer to the concerned usb core.
>>>>>>>> + *
>>>>>>>> + */
>>>>>>>> +static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
>>>>>>>> +{
>>>>>>>> + struct device *dev = qcom->dev;
>>>>>>>> + int ret;
>>>>>>>> +
>>>>>>>> + if (!device_is_bound(&qcom->dwc3->dev))
>>>>>>>> + return -EPROBE_DEFER;
>>>>>>> How is this supposed to work? I see that this was added in an earlier
>>>>>>> revision of this patch series but there isn't any mention of why
>>>>>>> device_is_bound() is used here. It would be great if there was a comment
>>>>>>> detailing why this is necessary. It sounds like maximum_speed is
>>>>>>> important?
>>>>>>>
>>>>>>> Furthermore, dwc3_qcom_interconnect_init() is called by
>>>>>>> dwc3_qcom_probe() which is the function that registers the device for
>>>>>>> qcom->dwc3->dev. If that device doesn't probe between the time it is
>>>>>>> registered by dwc3_qcom_probe() and this function is called then we'll
>>>>>>> fail dwc3_qcom_probe() with -EPROBE_DEFER. And that will remove the
>>>>>>> qcom->dwc3->dev device from the platform bus because we call
>>>>>>> of_platform_depopulate() on the error path of dwc3_qcom_probe().
>>>>>>>
>>>>>>> So isn't this whole thing racy and can potentially lead us to a driver
>>>>>>> probe loop where the wrapper (dwc3_qcom) and the core (dwc3) are probing
>>>>>>> and we're trying to time it just right so that driver for dwc3 binds
>>>>>>> before we setup interconnects? I don't know if dwc3 can communicate to
>>>>>>> the wrapper but that would be more of a direct way to do this. Or maybe
>>>>>>> the wrapper should try to read the DT property for maximum speed and
>>>>>>> fallback to a worst case high bandwidth value if it can't figure it out
>>>>>>> itself without help from dwc3 core.
>>>>>>>
>>>>>> This was added in V4 to address comments from Matthias in V3
>>>>>>
>>>>>> https://patchwork.kernel.org/patch/11148587/
>>>>>>
>>>>> Yes, that why I said:
>>>>>
>>>>> "I see that this was added in an earlier
>>>>> revision of this patch series but there isn't any mention of why
>>>>> device_is_bound() is used here. It would be great if there was a comment
>>>>> detailing why this is necessary. It sounds like maximum_speed is
>>>>> important?"
>>>>>
>>>>> Can you please respond to the rest of my email?
>>>> I agree with Stephen that using device_is_bound() isn't a good option
>>>> in this case, when I suggested it I wasn't looking at the big picture
>>>> of how probing the core driver is triggered, sorry about that.
>>>>
>>>> Reading the speed from the DT with usb_get_maximum_speed() as Stephen
>>>> suggests would be an option, the inconvenient is that we then
>>>> essentially require the property to be defined, while the core driver
>>>> gets a suitable value from hardware registers. Not sure if the wrapper
>>>> driver could read from the same registers.
>>>>
>>>> One option could be to poll device_is_bound() for 100 ms (or so), with
>>>> sleeps between polls. It's not elegant but would probably work if we
>>>> don't find a better solution.
>>> if (np)
>>>         ret = dwc3_qcom_of_register_core(pdev);
>>>     else
>>>         ret = dwc3_qcom_acpi_register_core(pdev);
>>>
>>>     if (ret) {
>>>         dev_err(dev, "failed to register DWC3 Core, err=%d\n", ret);
>>>         goto depopulate;
>>>     }
>>>
>>>     ret = dwc3_qcom_interconnect_init(qcom);
>>>     if (ret)
>>>         goto depopulate;
>>>
>>>     qcom->mode = usb_get_dr_mode(&qcom->dwc3->dev);
>>>
>>> Before calling dwc3_qcom_interconnect_init we are checking
>>>
>>>     if (ret) {
>>>         dev_err(dev, "failed to register DWC3 Core, err=%d\n", ret);
>>>         goto depopulate;
>>>     }
>>>
>>> Doesn't this condition confirm the core driver is probed?
>> Not really:
>>
>> // called under the hood by of_platform_populate()
>> static int really_probe(struct device *dev, struct device_driver *drv)
>> {
>> ...
>>
>> if (dev->bus->probe) {
>> ret = dev->bus->probe(dev);
>> if (ret)
>> goto probe_failed;
>> } else if (drv->probe) {
>> ret = drv->probe(dev);
>> if (ret)
>> goto probe_failed;
>> }
>>
>> ...
>>
>> probe_failed:
>> ...
>>
>> /*
>> * Ignore errors returned by ->probe so that the next driver can try
>> * its luck.
>> */
>> ret = 0;
>>
>> ...
>>
>> return ret;
>> }
>>
>> As a result of_platform_populate() in dwc3_qcom_of_register_core()
>> returns 0 even when probing the device failed:
>>
>> [ 0.244339] dwc3-qcom a6f8800.usb: DBG: populate
>> [ 0.244772] dwc3 a600000.dwc3: DBG: dwc3_probe
>> [ 0.245237] dwc3 a600000.dwc3: DBG: dwc3_probe err: -517
>> [ 0.245264] dwc3-qcom a6f8800.usb: DBG: populate (done)
>> [ 0.245317] dwc3-qcom a6f8800.usb: DBG: dwc3_qcom_interconnect_init() failed: -517
>>
>> Probe fails because the interconnect stuff isn't ready yet, otherwise
>> it could access invalid data.
>>
>> A later _populate() is successful and the probing of the core is done
>> synchronously, i.e. after _populate() the core driver is fully
>> initialized:
>>
>> [ 3.898106] dwc3-qcom a6f8800.usb: DBG: populate
>> [ 3.908356] dwc3 a600000.dwc3: DBG: dwc3_probe
>> [ 4.205104] dwc3 a600000.dwc3: DBG: dwc3_probe (done)
>> [ 4.210305] dwc3-qcom a6f8800.usb: DBG: populate (done)
>>
>> The synchronous probing in _populate() suggests that using device_is_bound()
>> would actually be a valid option, either the core device was successfully
>> probed or not, there should be no race.
>>
>> I sent a patch that adds this check to dwc3_qcom_of_register_core(), which
>> is less confusing and makes clear that the core device is valid unless
>> this function returns an error:
>>
>> https://lore.kernel.org/patchwork/patch/1257279/
>>
>> It might make sense to add your "driver core:Export the symbol
>> device_is_bound" patch, mine and this one to a single series.
> From the discussion on "driver core:Export the symbol device_is_bound"
> (https://patchwork.kernel.org/patch/11584225/) it is clear that
> this won't fly. The split dwc3 driver is considered a broken
> design.
>
> This is what Rob Herring said:
>
> We never should have had this split either in the DT binding nor
> driver(s) as if the SoC wrapper crap and licensed IP block are
> independent things. The thing to do here is either make the DWC3 code
> a library which drivers call (e.g. SDHCI) or add hooks into the DWC3
> driver for platform specifics (e.g. Designware PCI). Neither is a
> simple solution though.
>
> That seems to be the desirable solution in the longer term, but it
> doesn't seem reasonable to me to expect you to fix this design issue
> to add interconnect support.
>
> Some possible options to move forward:
>
> - try to determine the max speed without involving the core device
> - select a reasonable default when 'maximum-speed' is not specified
> - use the core device to determine the max speed and pray

Can we do as below to get speed

qcom->max_speed = usb_get_maximum_speed(&qcom->dwc3->dev);

as they were doing similarly in below code to get mode

qcom->mode = usb_get_dr_mode(&qcom->dwc3->dev);

--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

2020-07-07 15:53:34

by Matthias Kaehlcke

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Subject: Re: [PATCH v7 2/4] usb: dwc3: qcom: Add interconnect support in dwc3 driver

On Tue, Jul 07, 2020 at 10:41:24AM +0530, Sandeep Maheswaram (Temp) wrote:
>
> On 7/1/2020 4:12 AM, Matthias Kaehlcke wrote:
> > On Tue, Jun 16, 2020 at 01:38:49PM -0700, Matthias Kaehlcke wrote:
> > > On Tue, Jun 16, 2020 at 10:22:47AM +0530, Sandeep Maheswaram (Temp) wrote:
> > > > On 6/16/2020 1:12 AM, Matthias Kaehlcke wrote:
> > > > > On Thu, Jun 04, 2020 at 04:16:31AM -0700, Stephen Boyd wrote:
> > > > > > Quoting Sandeep Maheswaram (Temp) (2020-06-04 02:43:09)
> > > > > > > On 6/3/2020 11:06 PM, Stephen Boyd wrote:
> > > > > > > > Quoting Sandeep Maheswaram (2020-03-31 22:15:43)
> > > > > > > > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > > > > index 1dfd024..d33ae86 100644
> > > > > > > > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > > > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > > > > @@ -285,6 +307,101 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
> > > > > > > > > return 0;
> > > > > > > > > }
> > > > > > > > > +
> > > > > > > > > +/**
> > > > > > > > > + * dwc3_qcom_interconnect_init() - Get interconnect path handles
> > > > > > > > > + * @qcom: Pointer to the concerned usb core.
> > > > > > > > > + *
> > > > > > > > > + */
> > > > > > > > > +static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
> > > > > > > > > +{
> > > > > > > > > + struct device *dev = qcom->dev;
> > > > > > > > > + int ret;
> > > > > > > > > +
> > > > > > > > > + if (!device_is_bound(&qcom->dwc3->dev))
> > > > > > > > > + return -EPROBE_DEFER;
> > > > > > > > How is this supposed to work? I see that this was added in an earlier
> > > > > > > > revision of this patch series but there isn't any mention of why
> > > > > > > > device_is_bound() is used here. It would be great if there was a comment
> > > > > > > > detailing why this is necessary. It sounds like maximum_speed is
> > > > > > > > important?
> > > > > > > >
> > > > > > > > Furthermore, dwc3_qcom_interconnect_init() is called by
> > > > > > > > dwc3_qcom_probe() which is the function that registers the device for
> > > > > > > > qcom->dwc3->dev. If that device doesn't probe between the time it is
> > > > > > > > registered by dwc3_qcom_probe() and this function is called then we'll
> > > > > > > > fail dwc3_qcom_probe() with -EPROBE_DEFER. And that will remove the
> > > > > > > > qcom->dwc3->dev device from the platform bus because we call
> > > > > > > > of_platform_depopulate() on the error path of dwc3_qcom_probe().
> > > > > > > >
> > > > > > > > So isn't this whole thing racy and can potentially lead us to a driver
> > > > > > > > probe loop where the wrapper (dwc3_qcom) and the core (dwc3) are probing
> > > > > > > > and we're trying to time it just right so that driver for dwc3 binds
> > > > > > > > before we setup interconnects? I don't know if dwc3 can communicate to
> > > > > > > > the wrapper but that would be more of a direct way to do this. Or maybe
> > > > > > > > the wrapper should try to read the DT property for maximum speed and
> > > > > > > > fallback to a worst case high bandwidth value if it can't figure it out
> > > > > > > > itself without help from dwc3 core.
> > > > > > > >
> > > > > > > This was added in V4 to address comments from Matthias in V3
> > > > > > >
> > > > > > > https://patchwork.kernel.org/patch/11148587/
> > > > > > >
> > > > > > Yes, that why I said:
> > > > > >
> > > > > > "I see that this was added in an earlier
> > > > > > revision of this patch series but there isn't any mention of why
> > > > > > device_is_bound() is used here. It would be great if there was a comment
> > > > > > detailing why this is necessary. It sounds like maximum_speed is
> > > > > > important?"
> > > > > >
> > > > > > Can you please respond to the rest of my email?
> > > > > I agree with Stephen that using device_is_bound() isn't a good option
> > > > > in this case, when I suggested it I wasn't looking at the big picture
> > > > > of how probing the core driver is triggered, sorry about that.
> > > > >
> > > > > Reading the speed from the DT with usb_get_maximum_speed() as Stephen
> > > > > suggests would be an option, the inconvenient is that we then
> > > > > essentially require the property to be defined, while the core driver
> > > > > gets a suitable value from hardware registers. Not sure if the wrapper
> > > > > driver could read from the same registers.
> > > > >
> > > > > One option could be to poll device_is_bound() for 100 ms (or so), with
> > > > > sleeps between polls. It's not elegant but would probably work if we
> > > > > don't find a better solution.
> > > > if (np)
> > > >         ret = dwc3_qcom_of_register_core(pdev);
> > > >     else
> > > >         ret = dwc3_qcom_acpi_register_core(pdev);
> > > >
> > > >     if (ret) {
> > > >         dev_err(dev, "failed to register DWC3 Core, err=%d\n", ret);
> > > >         goto depopulate;
> > > >     }
> > > >
> > > >     ret = dwc3_qcom_interconnect_init(qcom);
> > > >     if (ret)
> > > >         goto depopulate;
> > > >
> > > >     qcom->mode = usb_get_dr_mode(&qcom->dwc3->dev);
> > > >
> > > > Before calling dwc3_qcom_interconnect_init we are checking
> > > >
> > > >     if (ret) {
> > > >         dev_err(dev, "failed to register DWC3 Core, err=%d\n", ret);
> > > >         goto depopulate;
> > > >     }
> > > >
> > > > Doesn't this condition confirm the core driver is probed?
> > > Not really:
> > >
> > > // called under the hood by of_platform_populate()
> > > static int really_probe(struct device *dev, struct device_driver *drv)
> > > {
> > > ...
> > >
> > > if (dev->bus->probe) {
> > > ret = dev->bus->probe(dev);
> > > if (ret)
> > > goto probe_failed;
> > > } else if (drv->probe) {
> > > ret = drv->probe(dev);
> > > if (ret)
> > > goto probe_failed;
> > > }
> > >
> > > ...
> > >
> > > probe_failed:
> > > ...
> > >
> > > /*
> > > * Ignore errors returned by ->probe so that the next driver can try
> > > * its luck.
> > > */
> > > ret = 0;
> > >
> > > ...
> > >
> > > return ret;
> > > }
> > >
> > > As a result of_platform_populate() in dwc3_qcom_of_register_core()
> > > returns 0 even when probing the device failed:
> > >
> > > [ 0.244339] dwc3-qcom a6f8800.usb: DBG: populate
> > > [ 0.244772] dwc3 a600000.dwc3: DBG: dwc3_probe
> > > [ 0.245237] dwc3 a600000.dwc3: DBG: dwc3_probe err: -517
> > > [ 0.245264] dwc3-qcom a6f8800.usb: DBG: populate (done)
> > > [ 0.245317] dwc3-qcom a6f8800.usb: DBG: dwc3_qcom_interconnect_init() failed: -517
> > >
> > > Probe fails because the interconnect stuff isn't ready yet, otherwise
> > > it could access invalid data.
> > >
> > > A later _populate() is successful and the probing of the core is done
> > > synchronously, i.e. after _populate() the core driver is fully
> > > initialized:
> > >
> > > [ 3.898106] dwc3-qcom a6f8800.usb: DBG: populate
> > > [ 3.908356] dwc3 a600000.dwc3: DBG: dwc3_probe
> > > [ 4.205104] dwc3 a600000.dwc3: DBG: dwc3_probe (done)
> > > [ 4.210305] dwc3-qcom a6f8800.usb: DBG: populate (done)
> > >
> > > The synchronous probing in _populate() suggests that using device_is_bound()
> > > would actually be a valid option, either the core device was successfully
> > > probed or not, there should be no race.
> > >
> > > I sent a patch that adds this check to dwc3_qcom_of_register_core(), which
> > > is less confusing and makes clear that the core device is valid unless
> > > this function returns an error:
> > >
> > > https://lore.kernel.org/patchwork/patch/1257279/
> > >
> > > It might make sense to add your "driver core:Export the symbol
> > > device_is_bound" patch, mine and this one to a single series.
> > From the discussion on "driver core:Export the symbol device_is_bound"
> > (https://patchwork.kernel.org/patch/11584225/) it is clear that
> > this won't fly. The split dwc3 driver is considered a broken
> > design.
> >
> > This is what Rob Herring said:
> >
> > We never should have had this split either in the DT binding nor
> > driver(s) as if the SoC wrapper crap and licensed IP block are
> > independent things. The thing to do here is either make the DWC3 code
> > a library which drivers call (e.g. SDHCI) or add hooks into the DWC3
> > driver for platform specifics (e.g. Designware PCI). Neither is a
> > simple solution though.
> >
> > That seems to be the desirable solution in the longer term, but it
> > doesn't seem reasonable to me to expect you to fix this design issue
> > to add interconnect support.
> >
> > Some possible options to move forward:
> >
> > - try to determine the max speed without involving the core device
> > - select a reasonable default when 'maximum-speed' is not specified
> > - use the core device to determine the max speed and pray
>
> Can we do as below to get speed
>
> qcom->max_speed = usb_get_maximum_speed(&qcom->dwc3->dev);

Yes, that would get the maximum speed from the DT if it is specified.
In case of USB_SPEED_UNKNOWN you probably want to assume it's
USB_SPEED_SUPER, which in the worst case would result in the ICC
running at a higher speed than needed.