[PATCH] arm: dts: imx7d-sdb: Fix enet by setting soft spi mode to 3 for extended io
This patch sets SPI MODE 3 for the fairchild 74HC595 device that is used to reset the ethernet device, which fixes ethernet.
Reasoning: The imx7dsabresd board uses SPI for setting the extended IO. One of the purposes of this extended IO, is having the ability to set ENET_RST i.e. reset the ethernet PHY. Without proper reset of the PHY, ethernet does not work.
commit 0e146993bb3d ("spi: add support for all spi modes with soft spi") broke network support for boards using imx7d-sdb, since it actually corrected default SPI mode setting for the software emulated soft_spi to 0, i.e. CPHA to 0 and CPOL to 0. Previously, the driver defaulted to CPHA 1 and CPOL 1 (i.e. spi mode 3). After the default SPI mode is now 0 (which is the correct default value) we now need to actively set CPHA and CPOL to 1 for the specific devices that actually needs this.
Signed-off-by: Christian Bräuner Sørensen yocto@bsorensen.net ---
arch/arm/dts/imx7d-sdb.dts | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm/dts/imx7d-sdb.dts b/arch/arm/dts/imx7d-sdb.dts index 8191ac7c33..6ed21ce8b0 100644 --- a/arch/arm/dts/imx7d-sdb.dts +++ b/arch/arm/dts/imx7d-sdb.dts @@ -58,6 +58,8 @@ reg = <0>; registers-number = <1>; spi-max-frequency = <100000>; + spi-cpha; + spi-cpol; }; };
Hi Christian,
On Fri, Feb 19, 2021 at 10:32 AM Christian Bräuner Sørensen yocto@bsorensen.net wrote:
This patch sets SPI MODE 3 for the fairchild 74HC595 device that is used to reset the ethernet device, which fixes ethernet.
Reasoning: The imx7dsabresd board uses SPI for setting the extended IO. One of the purposes of this extended IO, is having the ability to set ENET_RST i.e. reset the ethernet PHY. Without proper reset of the PHY, ethernet does not work.
commit 0e146993bb3d ("spi: add support for all spi modes with soft spi") broke network support for boards using imx7d-sdb, since it actually
Shouldn't this commit be reverted then?
I suppose it introduced regressions on other boards too.
corrected default SPI mode setting for the software emulated soft_spi to 0, i.e. CPHA to 0 and CPOL to 0. Previously, the driver defaulted to CPHA 1 and CPOL 1 (i.e. spi mode 3). After the default SPI mode is now 0 (which is the correct default value) we now need to actively set CPHA and CPOL to 1 for the specific devices that actually needs this.
Signed-off-by: Christian Bräuner Sørensen yocto@bsorensen.net
arch/arm/dts/imx7d-sdb.dts | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm/dts/imx7d-sdb.dts b/arch/arm/dts/imx7d-sdb.dts index 8191ac7c33..6ed21ce8b0 100644 --- a/arch/arm/dts/imx7d-sdb.dts +++ b/arch/arm/dts/imx7d-sdb.dts @@ -58,6 +58,8 @@ reg = <0>; registers-number = <1>; spi-max-frequency = <100000>;
spi-cphaspi-cpol;
It is not good that we deviate from the devicetree used in Linux.
Johannes/Jagan,
Any suggestions as to how to properly fix the regression?
Thanks
participants (2)
-
Christian Bräuner Sørensen -
Fabio Estevam