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

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

On Tue, May 26, 2015 at 02:23:37PM +0200, Alexander Aring wrote:
> 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])

meant == here, inverted logic.

> 			return  rdev_set_tx_power(...);
> 
> 	return -EINVAL;
> 
> 
> - Alex