| Message ID | 20210930155633.2745201-6-frieder@fris.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Devicetree fixes and additions for Kontron SL/BL i.MX8MM boards | expand |
On Thu, Sep 30, 2021 at 05:56:28PM +0200, Frieder Schrempf wrote: > From: Frieder Schrempf <frieder.schrempf@kontron.de> > > The MCP2515 can be used with an SPI clock of up to 10 MHz. Set the > limit accordingly to prevent any performance issues caused by the > really low clock speed of 100 kHz. Could you share some testing result of this change? > > Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards") It's really an optimization rather than fix, isn't it? Shawn > Cc: stable@vger.kernel.org > Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> > --- > arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts > index f2c8ccefd1bf..dbf11e03ecce 100644 > --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts > +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts > @@ -98,7 +98,7 @@ can0: can@0 { > clocks = <&osc_can>; > interrupt-parent = <&gpio4>; > interrupts = <28 IRQ_TYPE_EDGE_FALLING>; > - spi-max-frequency = <100000>; > + spi-max-frequency = <10000000>; > vdd-supply = <®_vdd_3v3>; > xceiver-supply = <®_vdd_5v>; > }; > -- > 2.33.0 >
On 05.10.21 09:12, Shawn Guo wrote: > On Thu, Sep 30, 2021 at 05:56:28PM +0200, Frieder Schrempf wrote: >> From: Frieder Schrempf <frieder.schrempf@kontron.de> >> >> The MCP2515 can be used with an SPI clock of up to 10 MHz. Set the >> limit accordingly to prevent any performance issues caused by the >> really low clock speed of 100 kHz. > > Could you share some testing result of this change? Without this change, receiving CAN messages on the board beyond a certain bitrate will cause overrun errors (see 'ip -det -stat link show can0'). With this fix, receiving messages on the bus works without any overrun errors for bitrates up to 1 MBit. > >> >> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards") > > It's really an optimization rather than fix, isn't it? It removes the arbitrarily low limit on the SPI frequency, that was caused by a typo in the original dts. As the usage of the CAN bus is seriously affected by this I would consider it a fix. But if you think otherwise, feel free to remove the Fixes tag. > > Shawn > >> Cc: stable@vger.kernel.org >> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> >> --- >> arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts >> index f2c8ccefd1bf..dbf11e03ecce 100644 >> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts >> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts >> @@ -98,7 +98,7 @@ can0: can@0 { >> clocks = <&osc_can>; >> interrupt-parent = <&gpio4>; >> interrupts = <28 IRQ_TYPE_EDGE_FALLING>; >> - spi-max-frequency = <100000>; >> + spi-max-frequency = <10000000>; >> vdd-supply = <®_vdd_3v3>; >> xceiver-supply = <®_vdd_5v>; >> }; >> -- >> 2.33.0 >>
On Tue, Oct 05, 2021 at 07:17:13PM +0200, Frieder Schrempf wrote: > On 05.10.21 09:12, Shawn Guo wrote: > > On Thu, Sep 30, 2021 at 05:56:28PM +0200, Frieder Schrempf wrote: > >> From: Frieder Schrempf <frieder.schrempf@kontron.de> > >> > >> The MCP2515 can be used with an SPI clock of up to 10 MHz. Set the > >> limit accordingly to prevent any performance issues caused by the > >> really low clock speed of 100 kHz. > > > > Could you share some testing result of this change? > > Without this change, receiving CAN messages on the board beyond a > certain bitrate will cause overrun errors (see 'ip -det -stat link show > can0'). > > With this fix, receiving messages on the bus works without any overrun > errors for bitrates up to 1 MBit. > > > > > >> > >> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards") > > > > It's really an optimization rather than fix, isn't it? > > It removes the arbitrarily low limit on the SPI frequency, that was > caused by a typo in the original dts. As the usage of the CAN bus is > seriously affected by this I would consider it a fix. But if you think > otherwise, feel free to remove the Fixes tag. Put all these good information into commit log, and I will be happy to take it as a fix. Shawn > >> Cc: stable@vger.kernel.org > >> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de> > >> --- > >> arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts > >> index f2c8ccefd1bf..dbf11e03ecce 100644 > >> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts > >> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts > >> @@ -98,7 +98,7 @@ can0: can@0 { > >> clocks = <&osc_can>; > >> interrupt-parent = <&gpio4>; > >> interrupts = <28 IRQ_TYPE_EDGE_FALLING>; > >> - spi-max-frequency = <100000>; > >> + spi-max-frequency = <10000000>; > >> vdd-supply = <®_vdd_3v3>; > >> xceiver-supply = <®_vdd_5v>; > >> }; > >> -- > >> 2.33.0 > >>
diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts index f2c8ccefd1bf..dbf11e03ecce 100644 --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts @@ -98,7 +98,7 @@ can0: can@0 { clocks = <&osc_can>; interrupt-parent = <&gpio4>; interrupts = <28 IRQ_TYPE_EDGE_FALLING>; - spi-max-frequency = <100000>; + spi-max-frequency = <10000000>; vdd-supply = <®_vdd_3v3>; xceiver-supply = <®_vdd_5v>; };