Re: [PATCH 1/2] phy: qcom: phy-qcom-snps-eusb2: Make repeater optional

[Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>]

On 3/19/25 12:35, Stephan Gerhold wrote:
> On Wed, Mar 19, 2025 at 12:20:07PM +0200, Dmitry Baryshkov wrote:
>> On Tue, Mar 18, 2025 at 10:22:56PM -0500, Bjorn Andersson via B4 Relay wrote:
>>> From: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
>>>
>>> In a multiport configuration based on the SNPS eUSB2 PHY it's not
>>> necessary that all ports are connected to something.
>>>
>>> While this is allowed by the Devicetree binding, the implementation
>>> current fails probing for such PHYs, which also prevents the multiport
>>> controller from probing.
>>>
>>> The lack of repeater does not alter the fact that the PHY is there and
>>> attempts at describing only the used PHYs in Devicetree results in
>>> failures to initialize the USB controller.
>>>
>>> Make the repeater optional, to allow the these PHYs to be described in
>>> the DeviceTree and for the associated multiport controller to operate
>>> the other ports.
>>>
>>> Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
>>> ---
>>>  drivers/phy/qualcomm/phy-qcom-snps-eusb2.c | 10 +++++++---
>>>  1 file changed, 7 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c b/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c
>>> index 1484691a41d59a7eaf257ef44300827c668bf7e0..8897d2072ccfcaa5b4a510c17761dcdeed5bad0f 100644
>>> --- a/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c
>>> +++ b/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c
>>> @@ -401,9 +401,13 @@ static int qcom_snps_eusb2_hsphy_probe(struct platform_device *pdev)
>>>  				     "failed to get regulator supplies\n");
>>>  
>>>  	phy->repeater = devm_of_phy_get_by_index(dev, np, 0);
>>> -	if (IS_ERR(phy->repeater))
>>> -		return dev_err_probe(dev, PTR_ERR(phy->repeater),
>>> -				     "failed to get repeater\n");
>>> +	if (IS_ERR(phy->repeater)) {
>>> +		if (PTR_ERR(phy->repeater) == -ENODEV)
>>> +			phy->repeater = NULL;
>>> +		else
>>> +			return dev_err_probe(dev, PTR_ERR(phy->repeater),
>>> +					     "failed to get repeater\n");
>> Can you use devm_of_phy_optional_get() or devm_phy_optional_get()
>> instead?
>>
> There is such a patch from Ivaylo already [1].
>
> @Ivaylo: Are you planning to re-spin that patch set?

Yes. I've spent the past week digging deeper into how my hardware works,
as well as improving the patchset.

>  Might be even worth
> putting that patch first / sending it separately, since Neil pointed out
> there that the bindings already have the repeater as non-required.

That's going to be... quite a bit of work. I have around 6-7 patches for this
driver alone, including moving the whole driver to ../, so moving this patch
to the front will be annoying.

Best regards,
Ivaylo

>
> Thanks,
> Stephan
>
> [1]: https://lore.kernel.org/linux-arm-msm/20250223122227.725233-6-ivo.ivanov.ivanov1@gmail.com/