From: Shawn Guo <shawnguo@kernel.org> To: Frieder Schrempf <frieder.schrempf@kontron.de> Cc: Frieder Schrempf <frieder@fris.de>, devicetree@vger.kernel.org, Krzysztof Kozlowski <krzk@kernel.org>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>, Sascha Hauer <s.hauer@pengutronix.de>, stable@vger.kernel.org, Fabio Estevam <festevam@gmail.com>, NXP Linux Team <linux-imx@nxp.com>, Pengutronix Kernel Team <kernel@pengutronix.de> Subject: Re: [PATCH 5/8] arm64: dts: imx8mm-kontron: Fix CAN SPI clock frequency Date: Fri, 15 Oct 2021 12:12:40 +0800 [thread overview] Message-ID: <20211015041239.GH22881@dragon> (raw) In-Reply-To: <37c1845d-9323-3187-ed0b-b9795758649d@kontron.de> 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 > >>
WARNING: multiple messages have this Message-ID (diff)
From: Shawn Guo <shawnguo@kernel.org> To: Frieder Schrempf <frieder.schrempf@kontron.de> Cc: Frieder Schrempf <frieder@fris.de>, devicetree@vger.kernel.org, Krzysztof Kozlowski <krzk@kernel.org>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>, Sascha Hauer <s.hauer@pengutronix.de>, stable@vger.kernel.org, Fabio Estevam <festevam@gmail.com>, NXP Linux Team <linux-imx@nxp.com>, Pengutronix Kernel Team <kernel@pengutronix.de> Subject: Re: [PATCH 5/8] arm64: dts: imx8mm-kontron: Fix CAN SPI clock frequency Date: Fri, 15 Oct 2021 12:12:40 +0800 [thread overview] Message-ID: <20211015041239.GH22881@dragon> (raw) In-Reply-To: <37c1845d-9323-3187-ed0b-b9795758649d@kontron.de> 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 > >> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-10-15 4:12 UTC|newest] Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-30 15:56 [PATCH 0/8] Devicetree fixes and additions for Kontron SL/BL i.MX8MM boards Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-09-30 15:56 ` [PATCH 1/8] arm64: dts: imx8mm-kontron: Add support for ultra high speed modes on SD card Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-10-05 6:45 ` Shawn Guo 2021-10-05 6:45 ` Shawn Guo 2021-10-15 10:44 ` Frieder Schrempf 2021-10-15 10:44 ` Frieder Schrempf 2021-09-30 15:56 ` [PATCH 2/8] arm64: dts: imx8mm-kontron: Make sure SOC and DRAM supply voltages are correct Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-09-30 16:02 ` Frieder Schrempf 2021-09-30 16:02 ` Frieder Schrempf 2021-10-05 6:49 ` Shawn Guo 2021-10-05 6:49 ` Shawn Guo 2021-10-05 6:53 ` Shawn Guo 2021-10-05 6:53 ` Shawn Guo 2021-10-05 13:10 ` Frieder Schrempf 2021-10-05 13:10 ` Frieder Schrempf 2021-10-15 3:51 ` Shawn Guo 2021-10-15 3:51 ` Shawn Guo 2021-09-30 15:56 ` [PATCH 3/8] arm64: dts: imx8mm-kontron: Set VDD_SNVS to 800 mV Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-10-05 6:56 ` Shawn Guo 2021-10-05 6:56 ` Shawn Guo 2021-10-05 13:14 ` Frieder Schrempf 2021-10-05 13:14 ` Frieder Schrempf 2021-10-15 4:04 ` Shawn Guo 2021-10-15 4:04 ` Shawn Guo 2021-09-30 15:56 ` [PATCH 4/8] arm64: dts: imx8mm-kontron: Fix reg_rst_eth2 and reg_vdd_5v regulators Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-10-05 7:09 ` Shawn Guo 2021-10-05 7:09 ` Shawn Guo 2021-10-05 17:06 ` Frieder Schrempf 2021-10-05 17:06 ` Frieder Schrempf 2021-10-15 4:09 ` Shawn Guo 2021-10-15 4:09 ` Shawn Guo 2021-10-15 11:32 ` Frieder Schrempf 2021-10-15 11:32 ` Frieder Schrempf 2021-09-30 15:56 ` [PATCH 5/8] arm64: dts: imx8mm-kontron: Fix CAN SPI clock frequency Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-10-05 7:12 ` Shawn Guo 2021-10-05 7:12 ` Shawn Guo 2021-10-05 17:17 ` Frieder Schrempf 2021-10-05 17:17 ` Frieder Schrempf 2021-10-15 4:12 ` Shawn Guo [this message] 2021-10-15 4:12 ` Shawn Guo 2021-09-30 15:56 ` [PATCH 6/8] arm64: dts: imx8mm-kontron: Fix connection type for VSC8531 RGMII PHY Frieder Schrempf 2021-10-02 18:14 ` Heiko Thiery 2021-10-02 18:08 ` Heiko Thiery 2021-10-05 7:20 ` Shawn Guo 2021-10-05 7:20 ` Shawn Guo 2021-09-30 15:56 ` [PATCH 7/8] arm64: dts: imx8mm-kontron: Fix reset delays for ethernet PHY Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-09-30 15:56 ` [PATCH 8/8] arm64: dts: imx8mm-kontron: Leave reg_vdd_arm always powered on Frieder Schrempf 2021-09-30 15:56 ` Frieder Schrempf 2021-09-30 18:52 ` Heiko Thiery 2021-09-30 18:52 ` Heiko Thiery 2021-10-05 7:27 ` Shawn Guo 2021-10-05 7:27 ` Shawn Guo
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