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Message-ID: <21ea292a-b1d1-43e2-92ab-9f1f63aaf729@samsung.com>
Date: Thu, 25 Apr 2024 21:40:32 +0200
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Subject: Re: [PATCH] usb: chipidea: move ci_ulpi_init after the phy
 initialization
To: 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
Content-Language: en-US
From: Marek Szyprowski <m.szyprowski@samsung.com>
In-Reply-To: <20240328-chipidea-phy-misc-v1-1-907d9de5d4df@pengutronix.de>
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References: <20240328-chipidea-phy-misc-v1-1-907d9de5d4df@pengutronix.de>
	<CGME20240425194033eucas1p2c1e98d1c55c970e246087e2dab180e84@eucas1p2.samsung.com>

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.

> ---
>   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
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland