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Message-ID: <87546d93-3fe7-4459-b44a-47cbcab9da74@me.ssier.org>
Date: Thu, 30 May 2024 02:38:25 -0400
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Subject: Re: [PATCH] usb: chipidea: move ci_ulpi_init after the phy
 initialization
To: Marek Szyprowski <m.szyprowski@samsung.com>,
 Michael Grzeschik <m.grzeschik@pengutronix.de>,
 Peter Chen <peter.chen@kernel.org>,
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
 regressions@lists.linux.dev, wouter@franken-peeters.be
References: <20240328-chipidea-phy-misc-v1-1-907d9de5d4df@pengutronix.de>
 <CGME20240425194033eucas1p2c1e98d1c55c970e246087e2dab180e84@eucas1p2.samsung.com>
 <21ea292a-b1d1-43e2-92ab-9f1f63aaf729@samsung.com>
Content-Language: en-US
From: Alexandre Messier <alex@me.ssier.org>
In-Reply-To: <21ea292a-b1d1-43e2-92ab-9f1f63aaf729@samsung.com>
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On 2024-04-25 15:40, Marek Szyprowski wrote:
> Dear All,
> 
> On 02.04.2024 08:23, Michael Grzeschik wrote:
>> The function ci_usb_phy_init is already handling the
>> hw_phymode_configure path which is also only possible after we have
>> a valid phy. So we move the ci_ulpi_init after the phy initialization
>> to be really sure to be able to communicate with the ulpi phy.
>>
>> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
> 
> This patch landed in linux-next some time ago as commit 22ffd399e6e7 
> ("usb: chipidea: move ci_ulpi_init after the phy initialization"). 
> Unfortunately it breaks host USB operation on DragonBoard410c 
> (arch/arm64/boot/dts/qcom/apq8016-sbc.dts). There is no error nor 
> warning in the kernel log besides the information about deferred probe 
> on the chipidea controller:
> 
> platform ci_hdrc.0: deferred probe pending: (reason unknown)
> 
> Tomorrow I will try to investigate which operation during driver probe 
> triggers it. If there is anything else to check that might help fixing 
> this issue, let me know.

I am also seeing this issue on a msm8974-based device.

There is also a report and analysis by Wouter Franken here:
https://lore.kernel.org/all/ecb8d3e8-d525-4a2d-a868-803202c16296@franken-peeters.be/

Reverting the commit does fix the issue for me.

Adding to regzbot for tracking:

#regzbot introduced: 22ffd399e6e7 ^

Thanks,
Alexandre

> 
>> ---
>>   drivers/usb/chipidea/core.c | 8 ++++----
>>   drivers/usb/chipidea/ulpi.c | 5 -----
>>   2 files changed, 4 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
>> index 835bf2428dc6e..bada13f704b62 100644
>> --- a/drivers/usb/chipidea/core.c
>> +++ b/drivers/usb/chipidea/core.c
>> @@ -1084,10 +1084,6 @@ static int ci_hdrc_probe(struct platform_device *pdev)
>>   		return -ENODEV;
>>   	}
>>   
>> -	ret = ci_ulpi_init(ci);
>> -	if (ret)
>> -		return ret;
>> -
>>   	if (ci->platdata->phy) {
>>   		ci->phy = ci->platdata->phy;
>>   	} else if (ci->platdata->usb_phy) {
>> @@ -1142,6 +1138,10 @@ static int ci_hdrc_probe(struct platform_device *pdev)
>>   		goto ulpi_exit;
>>   	}
>>   
>> +	ret = ci_ulpi_init(ci);
>> +	if (ret)
>> +		return ret;
>> +
>>   	ci->hw_bank.phys = res->start;
>>   
>>   	ci->irq = platform_get_irq(pdev, 0);
>> diff --git a/drivers/usb/chipidea/ulpi.c b/drivers/usb/chipidea/ulpi.c
>> index dfec07e8ae1d2..89fb51e2c3ded 100644
>> --- a/drivers/usb/chipidea/ulpi.c
>> +++ b/drivers/usb/chipidea/ulpi.c
>> @@ -68,11 +68,6 @@ int ci_ulpi_init(struct ci_hdrc *ci)
>>   	if (ci->platdata->phy_mode != USBPHY_INTERFACE_MODE_ULPI)
>>   		return 0;
>>   
>> -	/*
>> -	 * Set PORTSC correctly so we can read/write ULPI registers for
>> -	 * identification purposes
>> -	 */
>> -	hw_phymode_configure(ci);
>>   
>>   	ci->ulpi_ops.read = ci_ulpi_read;
>>   	ci->ulpi_ops.write = ci_ulpi_write;
>>
>> ---
>> base-commit: 5bab5dc780c9ed0c69fc2f828015532acf4a7848
>> change-id: 20240328-chipidea-phy-misc-b3f2bc814784
>>
>> Best regards,
> 
> Best regards