FAILED: patch "[PATCH] arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 5ae4dca718eacd0a56173a687a3736eb7e627c77
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025022438-automated-recycled-cc12@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5ae4dca718eacd0a56173a687a3736eb7e627c77 Mon Sep 17 00:00:00 2001
From: Lukasz Czechowski <lukasz.czechowski@thaumatec.com>
Date: Tue, 21 Jan 2025 13:56:04 +0100
Subject: [PATCH] arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

UART controllers without flow control seem to behave unstable
in case DMA is enabled. The issues were indicated in the message:
https://lore.kernel.org/linux-arm-kernel/CAMdYzYpXtMocCtCpZLU_xuWmOp2Ja_v0Aj0e6YFNRA-yV7u14g@mail.gmail.com/
In case of PX30-uQ7 Ringneck SoM, it was noticed that after couple
of hours of UART communication, the CPU stall was occurring,
leading to the system becoming unresponsive.
After disabling the DMA, extensive UART communication tests for
up to two weeks were performed, and no issues were further
observed.
The flow control pins for uart5 are not available on PX30-uQ7
Ringneck, as configured by pinctrl-0, so the DMA nodes were
removed on SoM dtsi.

Cc: stable@vger.kernel.org
Fixes: c484cf93f61b ("arm64: dts: rockchip: add PX30-µQ7 (Ringneck) SoM with Haikou baseboard")
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Lukasz Czechowski <lukasz.czechowski@thaumatec.com>
Link: https://lore.kernel.org/r/20250121125604.3115235-3-lukasz.czechowski@thaumatec.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi b/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
index 2c87005c89bd..e80412abec08 100644
--- a/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
+++ b/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
@@ -397,6 +397,8 @@ &u2phy_host {
 };
 
 &uart5 {
+	/delete-property/ dmas;
+	/delete-property/ dma-names;
 	pinctrl-0 = <&uart5_xfer>;
 };
 

Re: FAILED: patch "[PATCH] arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck" failed to apply to 6.6-stable tree

[Quentin Schulz]

Hi Greg, Heiko, Lukasz,

On 2/24/25 11:27 AM, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 6.6-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> To reproduce the conflict and resubmit, you may use the following commands:
> 
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
> git checkout FETCH_HEAD
> git cherry-pick -x 5ae4dca718eacd0a56173a687a3736eb7e627c77
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025022438-automated-recycled-cc12@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
> 
> Possible dependencies:
> 

Commit 5ae4dca718ea ("arm64: dts: rockchip: Disable DMA for uart5 on 
px30-ringneck") depends on 4eee627ea593 ("arm64: dts: rockchip: Move 
uart5 pin configuration to px30 ringneck SoM"), both slated for stable, 
so I'm surprised this patch is the one conflicting and not the first one 
(because it does conflict too!).

An option for clean application is to backport 5963d97aa780 ("arm64: 
dts: rockchip: add rs485 support on uart5 of px30-ringneck-haikou") to 
6.6 first, and then 4eee627ea593 followed by 5ae4dca718ea.

Another option is to resolve the conflict for 4eee627ea593 which is 
simply about the git context (rts-gpios can be removed if 5963d97aa780 
isn't backported).

@Heiko, @Greg, a preference on one of those two options (or a third one 
maybe?)? I personally would prefer the additional backport so we avoid 
other conflicts in the future (I already foresee one with a patch I 
posted (not merged yet!) last week).

Cheers,
Quentin

Re: FAILED: patch "[PATCH] arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck" failed to apply to 6.6-stable tree

[Greg KH]

On Mon, Feb 24, 2025 at 11:46:55AM +0100, Quentin Schulz wrote:
> Hi Greg, Heiko, Lukasz,
> 
> On 2/24/25 11:27 AM, gregkh@linuxfoundation.org wrote:
> > 
> > The patch below does not apply to the 6.6-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> > 
> > To reproduce the conflict and resubmit, you may use the following commands:
> > 
> > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x 5ae4dca718eacd0a56173a687a3736eb7e627c77
> > # <resolve conflicts, build, test, etc.>
> > git commit -s
> > git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025022438-automated-recycled-cc12@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
> > 
> > Possible dependencies:
> > 
> 
> Commit 5ae4dca718ea ("arm64: dts: rockchip: Disable DMA for uart5 on
> px30-ringneck") depends on 4eee627ea593 ("arm64: dts: rockchip: Move uart5
> pin configuration to px30 ringneck SoM"), both slated for stable, so I'm
> surprised this patch is the one conflicting and not the first one (because
> it does conflict too!).
> 
> An option for clean application is to backport 5963d97aa780 ("arm64: dts:
> rockchip: add rs485 support on uart5 of px30-ringneck-haikou") to 6.6 first,
> and then 4eee627ea593 followed by 5ae4dca718ea.
> 
> Another option is to resolve the conflict for 4eee627ea593 which is simply
> about the git context (rts-gpios can be removed if 5963d97aa780 isn't
> backported).
> 
> @Heiko, @Greg, a preference on one of those two options (or a third one
> maybe?)? I personally would prefer the additional backport so we avoid other
> conflicts in the future (I already foresee one with a patch I posted (not
> merged yet!) last week).

I don't care, it's your call, just submit a patch series of the
backported patches you want to see applied and I'll gladly take them.

thanks,

greg k-h

[PATCH 6.6.y] arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck

[Quentin Schulz]

From: Lukasz Czechowski <lukasz.czechowski@thaumatec.com>

UART controllers without flow control seem to behave unstable
in case DMA is enabled. The issues were indicated in the message:
https://lore.kernel.org/linux-arm-kernel/CAMdYzYpXtMocCtCpZLU_xuWmOp2Ja_v0Aj0e6YFNRA-yV7u14g@mail.gmail.com/
In case of PX30-uQ7 Ringneck SoM, it was noticed that after couple
of hours of UART communication, the CPU stall was occurring,
leading to the system becoming unresponsive.
After disabling the DMA, extensive UART communication tests for
up to two weeks were performed, and no issues were further
observed.
The flow control pins for uart5 are not available on PX30-uQ7
Ringneck, as configured by pinctrl-0, so the DMA nodes were
removed on SoM dtsi.

Cc: stable@vger.kernel.org
Fixes: c484cf93f61b ("arm64: dts: rockchip: add PX30-µQ7 (Ringneck) SoM with Haikou baseboard")
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Lukasz Czechowski <lukasz.czechowski@thaumatec.com>
Link: https://lore.kernel.org/r/20250121125604.3115235-3-lukasz.czechowski@thaumatec.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
(cherry picked from commit 5ae4dca718eacd0a56173a687a3736eb7e627c77)
[conflict resolution due to missing (cosmetic) backport of
 4eee627ea59304cdd66c5d4194ef13486a6c44fc]
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
---
 arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi b/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
index 5fcc5f32be2d7..2963d634baba9 100644
--- a/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
+++ b/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
@@ -367,6 +367,11 @@ &u2phy_host {
 	status = "okay";
 };
 
+&uart5 {
+	/delete-property/ dmas;
+	/delete-property/ dma-names;
+};
+
 /* Mule UCAN */
 &usb_host0_ehci {
 	status = "okay";

Re: [PATCH 6.6.y] arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: 5ae4dca718eacd0a56173a687a3736eb7e627c77

WARNING: Author mismatch between patch and found commit:
Backport author: Quentin Schulz<foss+kernel@0leil.net>
Commit author: Lukasz Czechowski<lukasz.czechowski@thaumatec.com>

Note: The patch differs from the upstream commit:
---
1:  5ae4dca718eac < -:  ------------- arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck
-:  ------------- > 1:  1efc320b58df2 arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |