From: Marc Kleine-Budde Date: Tue, 13 Aug 2019 14:01:02 +0000 (+0200) Subject: can: mcp251x: mcp251x_hw_reset(): allow more time after a reset X-Git-Tag: microblaze-v5.5-rc1~160^2~198^2~3 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=d84ea2123f8d27144e3f4d58cd88c9c6ddc799de;p=linux-2.6-microblaze.git can: mcp251x: mcp251x_hw_reset(): allow more time after a reset 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 --- diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index 1b3ac5f03f5b..74cb19a2bd08 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -606,7 +606,7 @@ static int mcp251x_setup(struct net_device *net, struct spi_device *spi) 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 */ @@ -620,10 +620,19 @@ 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; }