From: Doug Anderson <dianders@xxxxxxxxxxxx> If someone sends a EC_CMD_REBOOT_EC to the EC, the EC will likely be unresponsive for quite a while. Add a delay to the end of the command to prevent random failures of future commands. NOTES: * This could be optimized a bit by simply delaying the next command sent, but EC_CMD_REBOOT_EC is such a rare command that the extra complexity doesn't seem worth it. * This is a bit of an "ugly hack" since the SPI driver is effectively snooping on the communication and making a lot of assumptions. It would be nice to architect in some better solution long term. * This same logic probably needs to be applied to the i2c driver. Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx> Reviewed-by: Randall Spangler <rspangler@xxxxxxxxxxxx> Reviewed-by: Vadim Bendebury <vbendeb@xxxxxxxxxxxx> Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx> --- drivers/mfd/cros_ec_spi.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index 588c700..b396705 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -65,6 +65,12 @@ */ #define EC_SPI_RECOVERY_TIME_NS (200 * 1000) +/* + * The EC is unresponsive for a time after a reboot command. Add a + * simple delay to make sure that the bus stays locked. + */ +#define EC_REBOOT_DELAY_MS 50 + /** * struct cros_ec_spi - information about a SPI-connected EC * @@ -318,6 +324,9 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev, ret = len; exit: + if (ec_msg->command == EC_CMD_REBOOT_EC) + msleep(EC_REBOOT_DELAY_MS); + mutex_unlock(&ec_spi->lock); return ret; } -- 2.0.1 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
 |