On 19/08/2019 17.38, Marc Kleine-Budde wrote:
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@xxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Tested-by: Sean Nyekjaer <sean@xxxxxxxxxx>
---
drivers/net/can/spi/mcp251x.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 44b57187a6f3..db69c04bac2d 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;
}
