From 10e4ff82c512f6aa596046ee6ea52f6ad706366f Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Tue, 13 Aug 2019 16:01:02 +0200 Subject: [PATCH] can: mcp251x: mcp251x_hw_reset(): allow more time after a reset commit d84ea2123f8d27144e3f4d58cd88c9c6ddc799de upstream. Some boards take longer than 5ms to power up after a reset, so allow some retries attempts before giving up. Fixes: ff06d611a31c ("can: mcp251x: Improve mcp251x_hw_reset()") Cc: linux-stable Tested-by: Sean Nyekjaer Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/spi/mcp251x.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index ebf5ff5c3454..127366c3d9c8 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -655,7 +655,7 @@ static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv, static int mcp251x_hw_reset(struct spi_device *spi) { struct mcp251x_priv *priv = spi_get_drvdata(spi); - u8 reg; + unsigned long timeout; int ret; /* Wait for oscillator startup timer after power up */ @@ -669,10 +669,19 @@ static int mcp251x_hw_reset(struct spi_device *spi) /* Wait for oscillator startup timer after reset */ mdelay(MCP251X_OST_DELAY_MS); - reg = mcp251x_read_reg(spi, CANSTAT); - if ((reg & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF) - return -ENODEV; + /* Wait for reset to finish */ + timeout = jiffies + HZ; + while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) != + CANCTRL_REQOP_CONF) { + usleep_range(MCP251X_OST_DELAY_MS * 1000, + MCP251X_OST_DELAY_MS * 1000 * 2); + if (time_after(jiffies, timeout)) { + dev_err(&spi->dev, + "MCP251x didn't enter in conf mode after reset\n"); + return -EBUSY; + } + } return 0; }