From: Lucas Tanure <tanure@linux.com>
To: Neil Armstrong <neil.armstrong@linaro.org>,
Kevin Hilman <khilman@baylibre.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
Xianwei Zhao <xianwei.zhao@amlogic.com>,
linux-amlogic@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] arm64: dts: amlogic: t7: use the real UART pclk
Date: Tue, 18 Aug 2026 20:11:58 +0100 [thread overview]
Message-ID: <20260818191159.11523-2-tanure@linux.com> (raw)
In-Reply-To: <20260818191159.11523-1-tanure@linux.com>
uart_a lists the 24MHz crystal for all three of its clocks, because
the T7 clock controller driver did not exist when these boards were
added.
That leaves the real UART bus clock without a user, so the kernel
turns it off when it disables unused clocks at the end of boot, and
the board hangs.
Point uart_a at the real clocks, the way meson-s4.dtsi does, and drop
the placeholders from the two board files.
Fixes: 4fef056588f5 ("arm64: dts: amlogic-t7-a311d2-khadas-vim4: add initial device-tree")
Fixes: 6f048cc7a635 ("arm64: dts: add board AN400")
Signed-off-by: Lucas Tanure <tanure@linux.com>
Assisted-by: Claude:claude-fable-5
---
arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-an400.dts | 2 --
arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts | 2 --
arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi | 4 ++++
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-an400.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-an400.dts
index cab2ee9ea0d3..dcbcd08a78b9 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-an400.dts
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-an400.dts
@@ -33,7 +33,5 @@ xtal: xtal-clk {
};
&uart_a {
- clocks = <&xtal>, <&xtal>, <&xtal>;
- clock-names = "xtal", "pclk", "baud";
status = "okay";
};
diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
index c41525a34b72..677069e58f30 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
@@ -266,6 +266,4 @@ &sd_emmc_c {
&uart_a {
status = "okay";
- clocks = <&xtal>, <&xtal>, <&xtal>;
- clock-names = "xtal", "pclk", "baud";
};
diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
index cc371fcd1896..7847582e77ed 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
@@ -587,6 +587,10 @@ uart_a: serial@78000 {
compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
reg = <0x0 0x78000 0x0 0x18>;
interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
+ clocks = <&xtal>,
+ <&clkc_periphs CLKID_SYS_UART_A>,
+ <&xtal>;
+ clock-names = "xtal", "pclk", "baud";
status = "disabled";
};
--
2.55.0
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
next prev parent reply other threads:[~2026-08-18 19:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-18 19:11 [PATCH 0/2] arm64: dts: amlogic: t7: fix UART clock and SD card recovery Lucas Tanure
2026-08-18 19:11 ` Lucas Tanure [this message]
2026-08-18 19:11 ` [PATCH 2/2] arm64: dts: amlogic: t7: khadas-vim4: allow the SD card to be power cycled Lucas Tanure
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260818191159.11523-2-tanure@linux.com \
--to=tanure@linux.com \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=khilman@baylibre.com \
--cc=krzk+dt@kernel.org \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=neil.armstrong@linaro.org \
--cc=robh@kernel.org \
--cc=xianwei.zhao@amlogic.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox