On Wed, Apr 3, 2019 at 6:51 AM Enric Balletbo i Serra <[email protected]> wrote: > > The commit 9798ac6d32c1 ("mfd: cros_ec: Add cros_ec_cmd_xfer_status() > helper") was introduced to remove duplicated code in several users of > the cros_ec_cmd_xfer function. The idea behind that commit is mask all > the EC errors as protocol error when the EC command fails, what is > really useful because as a user you probably don't care of the exact > error reported by the EC, you only want to know if the command succeeded > or not. > > That works for most of the errors returned by the EC, but we might be > also interested on report the EC_RES_INVALID_COMMAND, which happens when > the command is not supported by the EC. An use case for this is when you > need to show/hide a sysfs attribute for a specific command and you don't > have a EC feature flag that tells you that the command is supported or > not. > > While here, also document properly the cros_ec_cmd_xfer_status > function. > > Signed-off-by: Enric Balletbo i Serra <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]> > --- > > drivers/platform/chrome/cros_ec_proto.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/platform/chrome/cros_ec_proto.c > b/drivers/platform/chrome/cros_ec_proto.c > index 97a068dff192..a4e0d3a6d891 100644 > --- a/drivers/platform/chrome/cros_ec_proto.c > +++ b/drivers/platform/chrome/cros_ec_proto.c > @@ -478,6 +478,16 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, > } > EXPORT_SYMBOL(cros_ec_cmd_xfer); > > +/** > + * cros_ec_cmd_xfer_status() - Send EC command. > + * @ec_dev: EC device. > + * @msg: EC message data for request and response. > + * > + * Return: > + * 0 - OK > + * -EINVAL - Invalid command. > + * -EPROTO - Protocol error. > + */ > int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev, > struct cros_ec_command *msg) > { > @@ -486,6 +496,11 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device > *ec_dev, > ret = cros_ec_cmd_xfer(ec_dev, msg); > if (ret < 0) { > dev_err(ec_dev->dev, "Command xfer error (err:%d)\n", ret); > + } else if (msg->result == EC_RES_INVALID_COMMAND) { > + dev_dbg(ec_dev->dev, > + "Command %d not supported for this device\n", > + msg->command); > + return -EINVAL; > } else if (msg->result != EC_RES_SUCCESS) { > dev_dbg(ec_dev->dev, "Command result (err: %d)\n", > msg->result); > return -EPROTO; > -- > 2.20.1 >
