On Thu, 18 Sep 2014, Javier Martinez Canillas wrote: > 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(+) Applied, thanks. > 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; > } -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
