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From: Thomas Kopp <thomas.kopp@microchip.com>
To: <linux-can@vger.kernel.org>
Cc: <mkl@pengutronix.de>, <kernel@pengutronix.de>,
	<dev.kurt@vandijck-laurijssen.be>,
	<manivannan.sadhasivam@linaro.org>
Subject: [PATCH] can: mcp25xxfd: Limit spiclk to 0.85*(sysclk/2)
Date: Wed, 16 Sep 2020 12:08:23 +0200	[thread overview]
Message-ID: <20200916100823.1105-1-thomas.kopp@microchip.com> (raw)

Signed-off-by: Thomas Kopp <thomas.kopp@microchip.com>
---
 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c
index 6ffa7af50119..670b7d1e1f46 100644
--- a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c
+++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c
@@ -2821,11 +2821,13 @@ static int mcp25xxfd_probe(struct spi_device *spi)
 	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	18750000 Hz	 93.75%	600000000 Hz	bad	assigned-clocks = <&ccu CLK_SPIx>
 	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 9090909 Hz	 90.09%	 18181819 Hz	good	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
 	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 9523809 Hz	 95.34%	 28571429 Hz	bad	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
+	 * 2517 40 MHz  atmel,sama5d27          atmel,at91rm9200-spi    16400000 Hz      82%     82000000 Hz    good    default
+	 * 2518 40 MHz  atmel,sama5d27          atmel,at91rm9200-spi    16400000 Hz      82%     82000000 Hz    good    default
 	 *
-	 * Limit SPI clock to 92.5% of SYSCLOCK / 2 for now.
+	 * Limit SPI clock to 85% of SYSCLOCK / 2 for now.
 	 */
 	priv->spi_max_speed_hz_orig = spi->max_speed_hz;
-	spi->max_speed_hz = min(spi->max_speed_hz, freq / 2 / 1000 * 925);
+	spi->max_speed_hz = min(spi->max_speed_hz, freq / 2 / 1000 * 850);
 	spi->bits_per_word = 8;
 	spi->rt = true;
 	err = spi_setup(spi);
-- 
2.25.1


             reply	other threads:[~2020-09-16 10:09 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-16 10:08 Thomas Kopp [this message]
2020-09-16 10:20 ` [PATCH] can: mcp25xxfd: Limit spiclk to 0.85*(sysclk/2) Marc Kleine-Budde

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