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

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Message-ID: <23e8f626-e512-4e80-b6b8-8ff073bd37e6@kernel.org>
Date: Sun, 16 Feb 2025 10:42:09 +0100
From: Krzysztof Kozlowski <krzk@...nel.org>
To: André Draszik <andre.draszik@...aro.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
 Vinod Koul <vkoul@...nel.org>, Kishon Vijay Abraham I <kishon@...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] phy: exynos5-usbdrd: Fix broken USB on Exynos5422 (TYPEC
 dependency)

On 15/02/2025 17:20, André Draszik wrote:
> Hi Krzysztof,
> 
> On Sat, 2025-02-15 at 10:41 +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 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.
>>
>> Drop incorrect dependency and rely on module to be reachable by the
>> compiler.
>>
>> 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
>> ---
>>  drivers/phy/samsung/Kconfig              | 1 -
>>  drivers/phy/samsung/phy-exynos5-usbdrd.c | 2 +-
>>  2 files changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/phy/samsung/Kconfig b/drivers/phy/samsung/Kconfig
>> index 7fba571c0e2b..e2330b0894d6 100644
>> --- a/drivers/phy/samsung/Kconfig
>> +++ b/drivers/phy/samsung/Kconfig
>> @@ -81,7 +81,6 @@ 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)
> 
> This line ensures that PHY_EXYNOS5_USBDRD changes to M if
> TYPEC is M.


I know what it does. But it is not the correct way to express optional
dependency. COMPILE_TEST makes no sense here. Unless this was not meant
to be optional dependency, but then it is wrong because none of older
(or many other) devices depend on typec.

> 
>>  	depends on USB_DWC3_EXYNOS
>>  	select GENERIC_PHY
>>  	select MFD_SYSCON
>> diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
>> index ff2436f11d68..e8a9fef22107 100644
>> --- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
>> +++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
>> @@ -1456,7 +1456,7 @@ static int exynos5_usbdrd_setup_notifiers(struct exynos5_usbdrd_phy *phy_drd)
>>  {
>>  	int ret;
>>  
>> -	if (!IS_ENABLED(CONFIG_TYPEC))
>> +	if (!IS_REACHABLE(CONFIG_TYPEC))
> 
> On arm64, the defconfig has TYPEC as module (while PHY_EXYNOS5_USBDRD
> defaults to y above), and therefore all following code is becomes
> disabled with your change on arm64.

In terms of defconfig, this could be fixed as simple as changing it to
module. This should be module for arm64, anyway.

In terms of users, that's indeed tricky runtime debugging issue, so
probably we need separate USBDRD_WITH_TYPEC symbol.

> 
> Can we find a different solution to unbreak arm32 and keep arm64
> defconfig working as intended?
> 
> Cheers,
> Andre'
> 


Best regards,
Krzysztof