Re: [PATCH v2 bluetooth-next] ieee802154: add set transmit power support

[Alexander Aring <alex.aring@gmail.com>]

On Tue, May 26, 2015 at 05:36:14PM +0530, Varka Bhadram wrote:
> Hi Alex,
> 
> On 05/26/2015 02:37 PM, Alexander Aring wrote:
> 
> >On Sun, May 24, 2015 at 08:16:33PM +0530, Varka Bhadram wrote:
> >>This patch adds transmission power setting support for IEEE-802.15.4
> >>devices via nl802154.
> >>
> >>Signed-off-by: Varka Bhadram <varkab@cdac.in>
> >>---
> >>  include/net/cfg802154.h   |    1 +
> >>  net/ieee802154/nl802154.c |   21 +++++++++++++++++++++
> >>  net/ieee802154/rdev-ops.h |   12 ++++++++++++
> >>  net/ieee802154/trace.h    |   15 +++++++++++++++
> >>  net/mac802154/cfg.c       |   19 +++++++++++++++++++
> >>  5 files changed, 68 insertions(+)
> >>
> >>diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
> >>index 4de59aa..2e3bb01 100644
> >>--- a/include/net/cfg802154.h
> >>+++ b/include/net/cfg802154.h
> >>@@ -44,6 +44,7 @@ struct cfg802154_ops {
> >>  	int	(*set_channel)(struct wpan_phy *wpan_phy, u8 page, u8 channel);
> >>  	int	(*set_cca_mode)(struct wpan_phy *wpan_phy,
> >>  				const struct wpan_phy_cca *cca);
> >>+	int     (*set_tx_power)(struct wpan_phy *wpan_phy, s32 power);
> >>  	int	(*set_pan_id)(struct wpan_phy *wpan_phy,
> >>  			      struct wpan_dev *wpan_dev, __le16 pan_id);
> >>  	int	(*set_short_addr)(struct wpan_phy *wpan_phy,
> >>diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
> >>index 54f4959..42bc3d7 100644
> >>--- a/net/ieee802154/nl802154.c
> >>+++ b/net/ieee802154/nl802154.c
> >>@@ -783,6 +783,19 @@ static int nl802154_set_cca_mode(struct sk_buff *skb, struct genl_info *info)
> >>  	return rdev_set_cca_mode(rdev, &cca);
> >>  }
> >>+static int nl802154_set_tx_power(struct sk_buff *skb, struct genl_info *info)
> >>+{
> >>+	struct cfg802154_registered_device *rdev = info->user_ptr[0];
> >>+	s32 power;
> >>+
> >>+	if (!info->attrs[NL802154_ATTR_TX_POWER])
> >>+		return -EINVAL;
> >>+
> >Uou also should check on phy tx power setting. That the phy is support
> >TX_POWER I moved this now, because it's phy setting (which ends into a
> >direct driver layer call) in the wpan_phy.
> >
> >it's (rdev->wpan_phy.flags & WPAN_PHY_FLAG_TXPOWER), so please do a:
> >
> >if (rdev->wpan_phy.flags & WPAN_PHY_FLAG_TXPOWER)
> >	return -EOPNOTSUPP;
> >
> >before the if (!info->attrs[NL802154_ATTR_TX_POWER]) condition.
> >
> Sure will do.
> 
> >Also we have now the option to first check on "if we support the
> >receiving mbm value". Please iterate over all these values before and
> >lookup if we support it.
> >
> >Since the TX_POWER is a direct layer call, normally the driver could
> >also report about "we don't support this value", but this depends on
> >driver implementation. So please check the value inside the cfg802154
> >layer, which makes it sure that the represented from capabilities can
> >really reach the driver layer only.
> >
> >How you iterate over the tx power values, you can lookup in capabilities
> >dump functionality.
> 
> What do you think about the following logic.?
> 
> 	...
>  	power = nla_get_s32(info->attrs[NL802154_ATTR_TX_POWER]);
> 
>         for  (i = 0; i < rdev->wpan_phy.supported.tx_powers_size; i++)
>                 if  (power != rdev->wpan_phy.supported.tx_powers[i])
>                         return  -EOPNOTSUPP;
> 
>         return  rdev_set_tx_power(rdev, power);

no, this makes no sense. Maybe something like:

	for  (i = 0; i < rdev->wpan_phy.supported.tx_powers_size; i++)
		if  (power != rdev->wpan_phy.supported.tx_powers[i])
			return  rdev_set_tx_power(...);

	return -EINVAL;


- Alex