| Message ID | 20210628151229.25214-1-pali@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] arm64: dts: armada-3720-turris-mox: remove mrvl, i2c-fast-mode | expand |
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>
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 >
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 {
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(+)