Bug 177847 - [ath] With TPC enabled, TX power values aren't clamped to the hardware maximum
Summary: [ath] With TPC enabled, TX power values aren't clamped to the hardware maximum
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: wireless (show other bugs)
Version: 1.0-CURRENT
Hardware: Any Any
: Normal Affects Only Me
Assignee: freebsd-wireless (Nobody)
Depends on:
Reported: 2013-04-14 06:00 UTC by Adrian Chadd
Modified: 2018-05-28 19:41 UTC (History)
0 users

See Also:


Note You need to log in before you can comment on or make changes to this bug.
Description Adrian Chadd freebsd_committer 2013-04-14 06:00:00 UTC
When TPC is enabled, the PHY doesn't necessarily clamp the TX power limit at the value programmed into the per-rate TX power registers.

For 11n chips, the HT20 and HT40 rates have a different adjustment to the programmed TX power values. Thus when doing TPC, the TX descriptor TX power register needs to be adjusted by that factor.

For later series chips (AR9280 and later), the TX descriptor TX power values need to be adjusted to account for the PHY minimum TX power being -2.5dBm, rather than 0 dBm (ie, instead of 0 == 0 dBm, 0 == -2.5dBm.)

For later later chips (AR9285), there are some differences between TX power levels for CCK, OFDM and HT rates.

How-To-Repeat: Enable TPC, see things go haywire.
Comment 1 Mark Linimon freebsd_committer freebsd_triage 2013-04-14 08:38:14 UTC
Responsible Changed
From-To: freebsd-bugs->freebsd-wireless

Over to maintainer(s).
Comment 2 Eitan Adler freebsd_committer freebsd_triage 2018-05-28 19:41:45 UTC
batch change:

For bugs that match the following
-  Status Is In progress 
- Untouched since 2018-01-01.
- Affects Base System OR Documentation


Reset to open status.

I did a quick pass but if you are getting this email it might be worthwhile to double check to see if this bug ought to be closed.