* [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl, i2c-fast-mode
@ 2021-06-28 12:10 ` Pali Rohár
0 siblings, 0 replies; 12+ messages in thread
From: Pali Rohár @ 2021-06-28 12:10 UTC (permalink / raw)
To: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Marek Behún, Russell King
Cc: linux-arm-kernel, devicetree, linux-kernel
Some SFP modules are not detected when i2c-fast-mode is enabled even when
clock-frequency is already set to 100000. The I2C bus violates the timing
specifications when run in fast mode. So disable fast mode on Turris Mox.
Same change was already applied for uDPU (also Armada 3720 board with SFP)
in commit fe3ec631a77d ("arm64: dts: uDPU: remove i2c-fast-mode").
Fixes: 7109d817db2e ("arm64: dts: marvell: add DTS for Turris Mox")
Signed-off-by: Pali Rohár <pali@kernel.org>
---
arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
index 6bcc319a0161..27ded36a1a13 100644
--- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
+++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
@@ -119,6 +119,7 @@
pinctrl-names = "default";
pinctrl-0 = <&i2c1_pins>;
clock-frequency = <100000>;
+ /delete-property/mrvl,i2c-fast-mode;
status = "okay";
rtc@6f {
--
2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl,i2c-fast-mode
2021-06-28 12:10 ` [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl, i2c-fast-mode Pali Rohár
@ 2021-06-28 13:05 ` Marek Behún
-1 siblings, 0 replies; 12+ messages in thread
From: Marek Behún @ 2021-06-28 13:05 UTC (permalink / raw)
To: Pali Rohár
Cc: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Russell King, linux-arm-kernel, devicetree, linux-kernel
On Mon, 28 Jun 2021 14:10:15 +0200
Pali Rohár <pali@kernel.org> wrote:
> + /delete-property/mrvl,i2c-fast-mode;
Can you add an additional space here?
/delete-property/ mrvl,i2c-fast-mode;
Other than that
Reviewed-by: Marek Behún <kabel@kernel.org>
BTW the i2c driver should me made to respect the `clock-frequency` DT
property, not the fast-mode nonsense.
The `mrvl,i2c-fast-mode` should be IMO completely removed and whether it
is enabled should be decided by the value of `clock-frequency`.
BTW there are clock generating registers in A3720 I2C controller that
can generate 100 kHz even in fast-mode. The driver does not use them,
though, it leaves them to their default values, which for normal mode
generate ~96 kHz and for fast mode ~258 kHz. Maybe we should implement
configuring these registers and make the driver choose
normal-mode / fast-mode / high-speed mode depending on
`clock-frequency` ?
Marek
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl,i2c-fast-mode
@ 2021-06-28 13:05 ` Marek Behún
0 siblings, 0 replies; 12+ messages in thread
From: Marek Behún @ 2021-06-28 13:05 UTC (permalink / raw)
To: Pali Rohár
Cc: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Russell King, linux-arm-kernel, devicetree, linux-kernel
On Mon, 28 Jun 2021 14:10:15 +0200
Pali Rohár <pali@kernel.org> wrote:
> + /delete-property/mrvl,i2c-fast-mode;
Can you add an additional space here?
/delete-property/ mrvl,i2c-fast-mode;
Other than that
Reviewed-by: Marek Behún <kabel@kernel.org>
BTW the i2c driver should me made to respect the `clock-frequency` DT
property, not the fast-mode nonsense.
The `mrvl,i2c-fast-mode` should be IMO completely removed and whether it
is enabled should be decided by the value of `clock-frequency`.
BTW there are clock generating registers in A3720 I2C controller that
can generate 100 kHz even in fast-mode. The driver does not use them,
though, it leaves them to their default values, which for normal mode
generate ~96 kHz and for fast mode ~258 kHz. Maybe we should implement
configuring these registers and make the driver choose
normal-mode / fast-mode / high-speed mode depending on
`clock-frequency` ?
Marek
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl,i2c-fast-mode
2021-06-28 12:10 ` [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl, i2c-fast-mode Pali Rohár
@ 2021-06-28 13:10 ` Marek Behún
-1 siblings, 0 replies; 12+ messages in thread
From: Marek Behún @ 2021-06-28 13:10 UTC (permalink / raw)
To: Pali Rohár
Cc: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Russell King, linux-arm-kernel, devicetree, linux-kernel
Also please remove ".dts" from commit title, i.e.:
arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
since "dts" is already present in the prefix.
Marek
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl,i2c-fast-mode
@ 2021-06-28 13:10 ` Marek Behún
0 siblings, 0 replies; 12+ messages in thread
From: Marek Behún @ 2021-06-28 13:10 UTC (permalink / raw)
To: Pali Rohár
Cc: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Russell King, linux-arm-kernel, devicetree, linux-kernel
Also please remove ".dts" from commit title, i.e.:
arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
since "dts" is already present in the prefix.
Marek
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
2021-06-28 12:10 ` [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl, i2c-fast-mode Pali Rohár
@ 2021-06-28 15:12 ` Pali Rohár
-1 siblings, 0 replies; 12+ messages in thread
From: Pali Rohár @ 2021-06-28 15:12 UTC (permalink / raw)
To: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Marek Behún, Russell King
Cc: linux-arm-kernel, devicetree, linux-kernel
Some SFP modules are not detected when i2c-fast-mode is enabled even when
clock-frequency is already set to 100000. The I2C bus violates the timing
specifications when run in fast mode. So disable fast mode on Turris Mox.
Same change was already applied for uDPU (also Armada 3720 board with SFP)
in commit fe3ec631a77d ("arm64: dts: uDPU: remove i2c-fast-mode").
Fixes: 7109d817db2e ("arm64: dts: marvell: add DTS for Turris Mox")
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <kabel@kernel.org>
---
arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
index 6bcc319a0161..85f15f2a4740 100644
--- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
+++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
@@ -119,6 +119,7 @@
pinctrl-names = "default";
pinctrl-0 = <&i2c1_pins>;
clock-frequency = <100000>;
+ /delete-property/ mrvl,i2c-fast-mode;
status = "okay";
rtc@6f {
--
2.20.1
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl, i2c-fast-mode
@ 2021-06-28 15:12 ` Pali Rohár
0 siblings, 0 replies; 12+ messages in thread
From: Pali Rohár @ 2021-06-28 15:12 UTC (permalink / raw)
To: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Marek Behún, Russell King
Cc: linux-arm-kernel, devicetree, linux-kernel
Some SFP modules are not detected when i2c-fast-mode is enabled even when
clock-frequency is already set to 100000. The I2C bus violates the timing
specifications when run in fast mode. So disable fast mode on Turris Mox.
Same change was already applied for uDPU (also Armada 3720 board with SFP)
in commit fe3ec631a77d ("arm64: dts: uDPU: remove i2c-fast-mode").
Fixes: 7109d817db2e ("arm64: dts: marvell: add DTS for Turris Mox")
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <kabel@kernel.org>
---
arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
index 6bcc319a0161..85f15f2a4740 100644
--- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
+++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
@@ -119,6 +119,7 @@
pinctrl-names = "default";
pinctrl-0 = <&i2c1_pins>;
clock-frequency = <100000>;
+ /delete-property/ mrvl,i2c-fast-mode;
status = "okay";
rtc@6f {
--
2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
2021-06-28 15:12 ` [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl, i2c-fast-mode Pali Rohár
@ 2021-06-28 16:16 ` Russell King (Oracle)
-1 siblings, 0 replies; 12+ messages in thread
From: Russell King (Oracle) @ 2021-06-28 16:16 UTC (permalink / raw)
To: Pali Rohár
Cc: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Marek Behún, linux-arm-kernel, devicetree, linux-kernel
On Mon, Jun 28, 2021 at 05:12:29PM +0200, Pali Rohár wrote:
> Some SFP modules are not detected when i2c-fast-mode is enabled even when
> clock-frequency is already set to 100000. The I2C bus violates the timing
> specifications when run in fast mode. So disable fast mode on Turris Mox.
Yes. SFP module specification is 100kHz max on the I2C bus, which is
often forgotten about until someone runs into a problem.
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
@ 2021-06-28 16:16 ` Russell King (Oracle)
0 siblings, 0 replies; 12+ messages in thread
From: Russell King (Oracle) @ 2021-06-28 16:16 UTC (permalink / raw)
To: Pali Rohár
Cc: Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring,
Marek Behún, linux-arm-kernel, devicetree, linux-kernel
On Mon, Jun 28, 2021 at 05:12:29PM +0200, Pali Rohár wrote:
> Some SFP modules are not detected when i2c-fast-mode is enabled even when
> clock-frequency is already set to 100000. The I2C bus violates the timing
> specifications when run in fast mode. So disable fast mode on Turris Mox.
Yes. SFP module specification is 100kHz max on the I2C bus, which is
often forgotten about until someone runs into a problem.
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
2021-06-28 15:12 ` [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl, i2c-fast-mode Pali Rohár
@ 2021-07-23 12:56 ` Gregory CLEMENT
-1 siblings, 0 replies; 12+ messages in thread
From: Gregory CLEMENT @ 2021-07-23 12:56 UTC (permalink / raw)
To: Pali Rohár, Andrew Lunn, Sebastian Hesselbarth, Rob Herring,
Marek Behún, Russell King
Cc: linux-arm-kernel, devicetree, linux-kernel
Hi Pali,
> Some SFP modules are not detected when i2c-fast-mode is enabled even when
> clock-frequency is already set to 100000. The I2C bus violates the timing
> specifications when run in fast mode. So disable fast mode on Turris Mox.
>
> Same change was already applied for uDPU (also Armada 3720 board with SFP)
> in commit fe3ec631a77d ("arm64: dts: uDPU: remove i2c-fast-mode").
>
> Fixes: 7109d817db2e ("arm64: dts: marvell: add DTS for Turris Mox")
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Reviewed-by: Marek Behún <kabel@kernel.org>
Applied on mvebu/fixes
Thanks,
Gregory
> ---
> arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> index 6bcc319a0161..85f15f2a4740 100644
> --- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> +++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> @@ -119,6 +119,7 @@
> pinctrl-names = "default";
> pinctrl-0 = <&i2c1_pins>;
> clock-frequency = <100000>;
> + /delete-property/ mrvl,i2c-fast-mode;
> status = "okay";
>
> rtc@6f {
> --
> 2.20.1
>
--
Gregory Clement, Bootlin
Embedded Linux and Kernel engineering
http://bootlin.com
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
@ 2021-07-23 12:56 ` Gregory CLEMENT
0 siblings, 0 replies; 12+ messages in thread
From: Gregory CLEMENT @ 2021-07-23 12:56 UTC (permalink / raw)
To: Pali Rohár, Andrew Lunn, Sebastian Hesselbarth, Rob Herring,
Marek Behún, Russell King
Cc: linux-arm-kernel, devicetree, linux-kernel
Hi Pali,
> Some SFP modules are not detected when i2c-fast-mode is enabled even when
> clock-frequency is already set to 100000. The I2C bus violates the timing
> specifications when run in fast mode. So disable fast mode on Turris Mox.
>
> Same change was already applied for uDPU (also Armada 3720 board with SFP)
> in commit fe3ec631a77d ("arm64: dts: uDPU: remove i2c-fast-mode").
>
> Fixes: 7109d817db2e ("arm64: dts: marvell: add DTS for Turris Mox")
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Reviewed-by: Marek Behún <kabel@kernel.org>
Applied on mvebu/fixes
Thanks,
Gregory
> ---
> arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> index 6bcc319a0161..85f15f2a4740 100644
> --- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> +++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> @@ -119,6 +119,7 @@
> pinctrl-names = "default";
> pinctrl-0 = <&i2c1_pins>;
> clock-frequency = <100000>;
> + /delete-property/ mrvl,i2c-fast-mode;
> status = "okay";
>
> rtc@6f {
> --
> 2.20.1
>
--
Gregory Clement, Bootlin
Embedded Linux and Kernel engineering
http://bootlin.com
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread