Date:   Tue, 2 Apr 2019 08:59:08 -0400
From:   Bob Copeland <me@bobcopeland.com>
To:     Balaji Pothunoori <bpothuno@codeaurora.org>
Cc:     johannes@sipsolutions.net, ath10k@lists.infradead.org,
        linux-wireless@vger.kernel.org,
        Ashok Raj Nagarajan <arnagara@codeaurora.org>
Subject: Re: [PATCH v4 1/3] cfg80211: Add support to set tx power for a
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On Tue, Apr 02, 2019 at 12:00:29PM +0530, Balaji Pothunoori wrote:
> > Should this really dBm?  It's a bit asymmetric for WIPHY_TX_POWER_LEVEL
> > to
> > use mBm and this to use dBm, and I might want to adjust in half-dB steps
> > if
> > supported by hardware.  Also allocating an s16 is a bit much for dBm.
> 
> if user will send mBm value then driver has to convert to dBm because
> firmware will expect the value in dBm.
> Please refer johannes comments on following patch " [EXT] Re: [PATCH] iw:
> Add support for controlling tx power for per station"
> for the reason why we opted dBm.

The quote was:

> I would prefer if this was *dBm*, rather than mBm, and be allowed to
> take float values, i.e. this would become "limit 20".

I read that as "iw should convert fractional dBm to mBm" not "kernel should
only support dBm".

ath10k might only support dBm, fine -- but even ath5k could support
per-packet transmit power in 0.5 dB steps, so this is already limiting
applicability to existing hardware.

-- 
Bob Copeland %% https://bobcopeland.com/