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From: Quentin Schulz <quentin.schulz@cherry.de>
To: Heiko Stuebner <heiko@sntech.de>,
	Alexey Charkov <alchark@gmail.com>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Manivannan Sadhasivam <mani@kernel.org>,
	Shawn Lin <shawn.lin@rock-chips.com>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH] arm64: dts: rockchip: Explicitly request UFS reset pin on RK3576
Date: Tue, 20 Jan 2026 11:21:34 +0100	[thread overview]
Message-ID: <8df14d73-8e20-4d89-89eb-d40f27814d2d@cherry.de> (raw)
In-Reply-To: <5743823.mogB4TqSGs@phil>

Hi Heiko,

On 1/20/26 9:55 AM, Heiko Stuebner wrote:
> Am Dienstag, 20. Januar 2026, 02:39:28 Mitteleuropäische Normalzeit schrieb Shawn Lin:
>> 在 2026/01/19 星期一 17:22, Alexey Charkov 写道:
>>> Rockchip RK3576 UFS controller uses a dedicated pin to reset the connected
>>> UFS device, which can operate either in a hardware controlled mode or as a
>>> GPIO pin.
>>>
>>
>> It's the only one 1.2V IO could be used on RK3576 to reset ufs devices,
>> except ufs refclk. So it's a dedicated pin for sure if using ufs, that's
>> why we put it into rk3576.dtsi.
>>
>>> Power-on default is GPIO mode, but the boot ROM reconfigures it to a
>>> hardware controlled mode if it uses UFS to load the next boot stage.
>>>
>>
>> ROM code could be specific, but the linux/loader driver is compatible,
>> so for the coming SoCs, with more 1.2V IO could be used, it's more
>> flexible to use gpio-based instead of hardware controlled(of course,
>> move reset pinctrl settings into board dts).
>>
>>> Given that existing bindings (and rk3576.dtsi) expect a GPIO-controlled
>>> device reset, request the required pin config explicitly.
>>>
>>> This doesn't appear to affect Linux, but it does affect U-boot:
>>>
>>
>> IIUC, it's more or less a fix for loader, more precisely U-boot here?
>> I'm not entirely certain about the handling here, is it standard
>> convention to add a fixes tag in this context?
> 
> Yes, a fixes tag is warranted here, in Linux it "only" fixes a potential
> issue due to the mismatch between pinconfig and gpio during probe.
> 
> nce this patch then enters the kernel, it can be cherry-picked to
> the current u-boot development cycle. I don't think u-boot is doing
> stable releases though, so U-Boot will only profit for the next
> version where this is included.
> 

U-Boot only takes what's in devicetree-rebasing 
(https://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasing.git), 
so only from Linus's tree AFAICT. C.f. 
https://docs.u-boot.org/en/latest/develop/process.html#resyncing-of-the-device-tree-subtree 
and 
https://docs.u-boot.org/en/latest/develop/devicetree/control.html#resyncing-with-devicetree-rebasing. 
See also OF_UPSTREAM Kconfig symbol in U-Boot.

This policy does make adding support for a new board quite slow as we 
may need to wait months before it makes it to Linus's tree, and then go 
through the development cycle in U-Boot which can also take a few months 
if the timing is unfortunate. For now it seems like we're sticking with 
this policy to avoid too much in "downstream" DT in U-Boot. I know we 
push for this aggressively for new Rockchip boards and SoCs, cannot say 
for other vendors.

Cheers,
Quentin

  reply	other threads:[~2026-01-20 10:21 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-19  9:22 Alexey Charkov
2026-01-19 11:08 ` Quentin Schulz
2026-01-19 13:43   ` Alexey Charkov
2026-01-19 13:58     ` Quentin Schulz
2026-01-19 14:05       ` Alexey Charkov
2026-01-19 14:42         ` Heiko Stübner
2026-01-20  9:21           ` Heiko Stuebner
2026-01-20  1:39 ` Shawn Lin
2026-01-20  7:13   ` Alexey Charkov
2026-01-20  8:55   ` Heiko Stuebner
2026-01-20 10:21     ` Quentin Schulz [this message]
2026-01-20 10:26       ` Heiko Stuebner

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