Re: [PATCH 3/3] phy: apple: atc: Implement the USB4 pipehandler state

[Sven Peter <sven@kernel.org>]

On 8/21/26 16:01, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
>
> New issues:
> - [High] Missing cleanup of `PIPEHANDLER_OVERRIDE` registers on lock failure leaves link detection permanently disabled.
>
> Pre-existing issues:
> - [High] Unconditional state update of `atcphy->pipehandler_up = true` on the error path masks hardware configuration failures.
> --
>
> --- Patch [3]: [PATCH 3/3] phy: apple: atc: Implement the USB4 pipehandler state ---
> commit 6b90c04f8cd4e7a3f818a4bc0eb1057996bb1845
> Author: Sven Peter <sven@kernel.org>
>
> phy: apple: atc: Implement the USB4 pipehandler state
>
> This commit implements the USB4 pipehandler state for the Apple ATC PHY driver.
> It switches the dwc3's PIPE interface to the USB4 NHI which takes care of
> tunneling USB3 over USB4.
>
>> diff --git a/drivers/phy/apple/atc.c b/drivers/phy/apple/atc.c
>> index 96158d3486560..613bcd0ae8865 100644
>> --- a/drivers/phy/apple/atc.c
>> +++ b/drivers/phy/apple/atc.c
>> @@ -1084,6 +1084,41 @@ static int atcphy_configure_pipehandler_usb3(struct apple_atcphy *atcphy, bool h
>>   	return 0;
>>   }
>>   
>> +static int atcphy_configure_pipehandler_usb4(struct apple_atcphy *atcphy)
>> +{
>> +	int ret;
>> +
>> +	ret = atcphy_pipehandler_check(atcphy);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Force disable link detection */
>> +	clear32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE_VALUES,
>> +		PIPEHANDLER_OVERRIDE_VAL_RXDETECT0 | PIPEHANDLER_OVERRIDE_VAL_RXDETECT1);
>> +	set32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE, PIPEHANDLER_OVERRIDE_RXVALID);
>> +	set32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE, PIPEHANDLER_OVERRIDE_RXDETECT);
>> +
>> +	ret = atcphy_pipehandler_lock(atcphy);
>> +	if (ret) {
>> +		dev_err(atcphy->dev, "Failed to lock pipehandler\n");
>> +		return ret;
>> +	}
> [Severity: High]
> If atcphy_pipehandler_lock() fails and returns early, the link detection
> override bits (PIPEHANDLER_OVERRIDE_RXVALID and
> PIPEHANDLER_OVERRIDE_RXDETECT) are left set.
>
> Does this permanently disable link detection on the PHY hardware for
> subsequent retries until a hard reset occurs?

No, if this fails the port will be broken until the next unplug/plug 
which resets everything anyway.
Same pattern has been working in the other paths and since we have no 
documentation for this PHY I won't touch it or do anything else here.



Sven


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