Hello, Given we've not found a direct solution and multiple people still have problems with this, would it be acceptable to expose the delay as a module parameter for the time being so people experiencing issues can work around it without having to rebuild the kernel for now? Patch attached. Regards, Andreas Henriksson
>From 2476da179345108909f9722b6d30322904fc987b Mon Sep 17 00:00:00 2001 From: Andreas Henriksson <andreas.henriksson@xxxxxxxxx> Date: Thu, 24 Jan 2019 19:17:13 +0100 Subject: [PATCH] mcp251x: make reset delay a module parameter --- drivers/net/can/spi/mcp251x.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index e90817608645..9195f4ca3af3 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -219,6 +219,10 @@ #define DEVICE_NAME "mcp251x" +static int mcp251x_ost_delay_ms = MCP251X_OST_DELAY_MS; +module_param(mcp251x_ost_delay_ms, int, 0444); +MODULE_PARM_DESC(mcp251x_ost_delay_ms, "SPI reset delay in milliseconds"); + static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */ module_param(mcp251x_enable_dma, int, 0444); MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)"); @@ -630,7 +634,7 @@ static int mcp251x_hw_reset(struct spi_device *spi) int ret; /* Wait for oscillator startup timer after power up */ - mdelay(MCP251X_OST_DELAY_MS); + mdelay(mcp251x_ost_delay_ms); priv->spi_tx_buf[0] = INSTRUCTION_RESET; ret = mcp251x_spi_trans(spi, 1); @@ -638,7 +642,7 @@ static int mcp251x_hw_reset(struct spi_device *spi) return ret; /* Wait for oscillator startup timer after reset */ - mdelay(MCP251X_OST_DELAY_MS); + mdelay(mcp251x_ost_delay_ms); reg = mcp251x_read_reg(spi, CANSTAT); if ((reg & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF) -- 2.20.1
