| From a2513071913326cdf2076d59ead71e40b5a620a7 Mon Sep 17 00:00:00 2001 |
| From: Marc Kleine-Budde <mkl@pengutronix.de> |
| 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 <stable@vger.kernel.org> |
| Tested-by: Sean Nyekjaer <sean@geanix.com> |
| Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c |
| index 2aec934fab0c..fc29252500c6 100644 |
| --- a/drivers/net/can/spi/mcp251x.c |
| +++ b/drivers/net/can/spi/mcp251x.c |
| @@ -612,7 +612,7 @@ 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 */ |
| @@ -626,10 +626,19 @@ 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; |
| } |
| |
| -- |
| 2.7.4 |
| |