diff mbox series

[2/2] ARM: dts: imx6ull-tarragon: Reduce SPI clock for QCA7000

Message ID 20240416190659.15430-3-wahrenst@gmx.net (mailing list archive)
State New
Headers show
Series ARM: dts: imx6ull-tarragon: Minor changes | expand

Commit Message

Stefan Wahren April 16, 2024, 7:06 p.m. UTC
Our hardware department recently informed us that, according to
the specification, the QCA7000 should be operated with a
maximum SPI clock frequency of 12 MHz. Even if it appears to work
at a higher frequency, we should not take any risks here. A short
performance test showed no measurable loss of speed.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts  | 4 ++--
 arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts   | 2 +-
 arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

--
2.34.1

Comments

Fabio Estevam April 17, 2024, 3 a.m. UTC | #1
Hi Stefan,

On Tue, Apr 16, 2024 at 4:07 PM Stefan Wahren <wahrenst@gmx.net> wrote:
>
> Our hardware department recently informed us that, according to
> the specification, the QCA7000 should be operated with a
> maximum SPI clock frequency of 12 MHz. Even if it appears to work
> at a higher frequency, we should not take any risks here. A short
> performance test showed no measurable loss of speed.

Should this one have a Fixes tag?
Stefan Wahren April 17, 2024, 10:44 a.m. UTC | #2
Hi Fabio,

Am 17.04.24 um 05:00 schrieb Fabio Estevam:
> Hi Stefan,
>
> On Tue, Apr 16, 2024 at 4:07 PM Stefan Wahren <wahrenst@gmx.net> wrote:
>> Our hardware department recently informed us that, according to
>> the specification, the QCA7000 should be operated with a
>> maximum SPI clock frequency of 12 MHz. Even if it appears to work
>> at a higher frequency, we should not take any risks here. A short
>> performance test showed no measurable loss of speed.
> Should this one have a Fixes tag?
i'm undecided about that. On the one hand the the former clock
frequencies are wrong, on the other hand we didn't experience any issues
with these frequencies.
diff mbox series

Patch

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts
index 67007ce383e3..f9bbd589b66d 100644
--- a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts
@@ -45,7 +45,7 @@  &pinctrl_qca700x_cp_rst
 		interrupts = <19 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };

@@ -63,7 +63,7 @@  &pinctrl_qca700x_mains_rst
 		interrupts = <9 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts
index cee223b5f8e1..ef06619d7c86 100644
--- a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts
@@ -23,7 +23,7 @@  &pinctrl_qca700x_cp_rst
 		interrupts = <19 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts
index 7fd53b7a4372..83db65bf630f 100644
--- a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts
@@ -45,7 +45,7 @@  &pinctrl_qca700x_cp_rst
 		interrupts = <19 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };