Hi,
Thanks for the quick respin, two few comments below
On 28/6/19 16:41, Fabien Lahoudere wrote:
> This patch adds a function to determine which version of the
> protocol is used to communicate with EC.
>
> Signed-off-by: Fabien Lahoudere <fabien.lahoudere@xxxxxxxxxxxxx>
> Signed-off-by: Nick Vaccaro <nvaccaro@xxxxxxxxxxxx>
The order must be the opposite, first Nick and then you.
> ---
> .../cros_ec_sensors/cros_ec_sensors_core.c | 40 ++++++++++++++++++-
> 1 file changed, 39 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> index 130362ca421b..75d9b617f6c8 100644
> --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> @@ -25,6 +25,35 @@ static char *cros_ec_loc[] = {
> [MOTIONSENSE_LOC_MAX] = "unknown",
> };
>
> +static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
> + u16 cmd_offset, u16 cmd, u32 *mask)
> +{
> + int ret;
> + struct {
> + struct cros_ec_command msg;
> + union {
> + struct ec_params_get_cmd_versions params;
> + struct ec_response_get_cmd_versions resp;
> + };
> + } __packed buf = {
> + .msg = {
> + .version = 0,
> + .command = EC_CMD_GET_CMD_VERSIONS + cmd_offset,
> + .insize = sizeof(struct ec_response_get_cmd_versions),
> + .outsize = sizeof(struct ec_params_get_cmd_versions)
> + },
> + .params = {.cmd = cmd}
> + };
> +
> + ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
> + if (ret < 0)
> + return ret;
> +
> + *mask = buf.resp.version_mask;
> +
> + return 0;
> +}
> +
> int cros_ec_sensors_core_init(struct platform_device *pdev,
> struct iio_dev *indio_dev,
> bool physical_device)
> @@ -33,6 +62,8 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
> struct cros_ec_dev *ec = dev_get_drvdata(pdev->dev.parent);
> struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
> + u32 ver_mask;
If you follow the error path in the cros_ec_get_host_cmd_version_mask there is a
possible use of an uninitialized variable.
u32 ver_mask = 0;
> + int ret;
>
> platform_set_drvdata(pdev, indio_dev);
>
> @@ -47,8 +78,15 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
>
> mutex_init(&state->cmd_lock);
>
What about adding a comment to explain the ver_mask thing for the record?
/*
* If the EC is very old or misbehaving is it possible that the
* communication succeed and have the version mask set to an invalid
* value. So check that version mask is valid (!= 0), otherwise return
* an error.
*/
At least this is what I understood from the previous discussion.
> + ret = cros_ec_get_host_cmd_version_mask(state->ec,
> + ec->cmd_offset,
> + EC_CMD_MOTION_SENSE_CMD,
> + &ver_mask);
> + if (ret < 0 || ver_mask == 0)
> + return -ENODEV;
> +
> /* Set up the host command structure. */
> - state->msg->version = 2;
> + state->msg->version = fls(ver_mask) - 1;;
> state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
> state->msg->outsize = sizeof(struct ec_params_motion_sense);
>
>
Thanks,
~ Enric
