linux-kernel - Re: [PATCH v2] phy: exynos5-usbdrd: Fix broken USB on Exynos5422 (TYPEC dependency)

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Message-ID: <88b00cc53cd5cb3682a29d6a2ec491c7640129ce.camel@linaro.org>
Date: Mon, 17 Feb 2025 05:59:51 +0000
From: André Draszik <andre.draszik@...aro.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>, Vinod Koul
 <vkoul@...nel.org>, Kishon Vijay Abraham I <kishon@...nel.org>, Krzysztof
 Kozlowski <krzk@...nel.org>, Alim Akhtar <alim.akhtar@...sung.com>, Peter
 Griffin <peter.griffin@...aro.org>, linux-phy@...ts.infradead.org, 
 linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
 linux-samsung-soc@...r.kernel.org
Cc: Marek Szyprowski <m.szyprowski@...sung.com>
Subject: Re: [PATCH v2] phy: exynos5-usbdrd: Fix broken USB on Exynos5422
 (TYPEC dependency)

Hi Krzysztof,

On Sun, 2025-02-16 at 12:41 +0100, Krzysztof Kozlowski wrote:
> Older Exynos designs, like Exynos5422, do not have USB Type-C and the
> USB DRD PHY does not really depend on Type-C for these devices at all.
> Incorrectly added optional dependency on CONFIG_TYPEC caused this driver
> to be missing for exynos_defconfig and as result Exynos5422-based boards
> like Hardkernel Odroid HC1 failed to probe USB.
> 
> However ARM64 boards should have CONFIG_TYPEC enabled and in proper
> state (e.g. =y when PHY_EXYNOS5_USBDRD is =y) for proper USB support on
> Google GS101 boards.
> 
> Add itermediate CONFIG_PHY_EXYNOS5_USBDRD_TYPEC symbol to skip TYPEC on
> older boards, while still expressing optional dependency.
> 
> Reported-by: Krzysztof Kozlowski <krzk@...nel.org>
> Closes: https://krzk.eu/#/builders/21/builds/6139
> Reported-by: Marek Szyprowski <m.szyprowski@...sung.com>
> Closes: https://lore.kernel.org/all/3c0b77e6-357d-453e-8b63-4757c3231bde@samsung.com/
> Fixes: 09dc674295a3 ("phy: exynos5-usbdrd: subscribe to orientation notifier if required")
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
> 
> ---
> 
> Patch for issue in linux-next
> 
> Changes in v2:
> 1. Add PHY_EXYNOS5_USBDRD_TYPEC, so arm64 defconfig will have both
>    symbols in-sync
> ---
>  drivers/phy/samsung/Kconfig              | 12 +++++++++++-
>  drivers/phy/samsung/phy-exynos5-usbdrd.c |  1 +
>  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/samsung/Kconfig b/drivers/phy/samsung/Kconfig
> index 7fba571c0e2b..b20ac6b75993 100644
> --- a/drivers/phy/samsung/Kconfig
> +++ b/drivers/phy/samsung/Kconfig
> @@ -77,12 +77,22 @@ config PHY_S5PV210_USB2
>  	  particular SoC is compiled in the driver. In case of S5PV210 two phys
>  	  are available - device and host.
>  
> +# None of ARM32 Samsung boards use Type-C, however newer ARM64 do and
> +# PHY_EXYNOS5_USBDRD driver needs TYPEC to be in a matching state to avoid link
> +# failures (see optional dependencies in kconfig-language.rst).  Intermediate
> +# PHY_EXYNOS5_USBDRD_TYPEC symbol allows to skip TYPEC on ARM32 boards.
> +config PHY_EXYNOS5_USBDRD_TYPEC
> +	tristate
> +	depends on ARCH_EXYNOS
> +	depends on ARM || TYPEC || !TYPEC
> +	default y
> +
>  config PHY_EXYNOS5_USBDRD
>  	tristate "Exynos5 SoC series USB DRD PHY driver"
>  	depends on (ARCH_EXYNOS && OF) || COMPILE_TEST
>  	depends on HAS_IOMEM
> -	depends on TYPEC || (TYPEC=n && COMPILE_TEST)

Is it not possible to just drop the '&& COMPILE_TEST' part to make
it
  depends on TYPEC || TYPEC=n
or
  depends on TYPEC || !TYPEC
(without any of the other changes)?

If not, why not, are there corner cases that doesn't catch? Some
minimal testing seems to suggest that that works, too.

Cheers,
Andre'

>  	depends on USB_DWC3_EXYNOS
> +	depends on PHY_EXYNOS5_USBDRD_TYPEC
>  	select GENERIC_PHY
>  	select MFD_SYSCON
>  	default y
> diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> index ff2436f11d68..6d571dff2898 100644
> --- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
> +++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> @@ -1456,6 +1456,7 @@ static int exynos5_usbdrd_setup_notifiers(struct exynos5_usbdrd_phy *phy_drd)
>  {
>  	int ret;
>  
> +	/* See CONFIG_PHY_EXYNOS5_USBDRD_TYPEC */
>  	if (!IS_ENABLED(CONFIG_TYPEC))
>  		return 0;
>