On Wed, 2009-02-18 at 07:18 -0500, Dan Williams wrote:
[snipped explanation]
> Anyone think all this stuff really, really sucks? Yes!!! So lets just
> have drivers/stack provide a few sane values that userspace really
> doesn't have to go through this shit to calculate...
>
> <rant ends>
>
> NM is probably fine here with qual == 0 because I doubt the GIWRANGE
> handler is returning a valid max_qual.qual > 0 anymore with Johannes'
> patch. Could be wrong though.
We're actually getting _two_ things wrong now and nobody ever noticed.
So much for "but someone might care about the values wext returns". But
there actually is a problem.
First, we're reporting max_qual.qual != 0 still, this should be changed.
wpa_supplicant is still reporting quality values, so the invalid flags
aren't ever set. This needs to change in mac80211 (fixing the immediate
regression) and wpa_supplicant.
HOWEVER. Since all our qual.qual values are 0 though, your code _should_
cope fine, because of this (from NM):
/* If the quality percent was 0 or doesn't exist, then try to use signal levels instead */
if ((percent < 1) && (level_percent >= 0))
percent = level_percent;
Now, why doesn't it?
Because we don't report proper max_qual _level_ values. Something
clearly nobody cared about because NM was using qual.qual and not
qual.level. Here's the relevant snippet from mac80211:
/* cfg80211 requires this, and enforces 0..100 */
if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
range->max_qual.level = 100;
else if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
range->max_qual.level = -110;
else
range->max_qual.level = 0;
Note the dBm branch -- clearly wrong. Did anyone care? Clearly not.
Therefore, here's what I'm going to do:
1) always set IW_QUAL_QUAL_INVALID, even in max_qual (fixes bug #1)
2) set max_qual.level to 0 for dBm instead of -110 (fixes bug #2)
patch below.
johannes
Subject: mac80211: fix wext max_qual report
mac80211 is reporting a max_qual.level of -110 for dBm while it
should be reporting 0. It is also reporting a valid max_qual.qual
although we no longer set qual.qual, which trips up NetworkManager
due to a wpa_supplicant bug. But we don't need to report that our
max_qual.qual value is valid.
Fix the max_qual.level to be 0 for dBm and 100 for non-dBm and
remove max_qual.qual. max_qual.noise = -110 also seems wrong,
so fix that while at it.
Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
---
net/mac80211/wext.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
--- wireless-testing.orig/net/mac80211/wext.c 2009-02-18 14:24:56.000000000 +0100
+++ wireless-testing/net/mac80211/wext.c 2009-02-18 14:29:07.000000000 +0100
@@ -148,11 +148,19 @@ static u8 ieee80211_get_wstats_flags(str
{
u8 wstats_flags = 0;
- wstats_flags |= local->hw.flags & (IEEE80211_HW_SIGNAL_UNSPEC |
- IEEE80211_HW_SIGNAL_DBM) ?
- IW_QUAL_QUAL_UPDATED : IW_QUAL_QUAL_INVALID;
- wstats_flags |= local->hw.flags & IEEE80211_HW_NOISE_DBM ?
- IW_QUAL_NOISE_UPDATED : IW_QUAL_NOISE_INVALID;
+ wstats_flags |= IW_QUAL_QUAL_INVALID;
+
+ if (local->hw.flags & (IEEE80211_HW_SIGNAL_UNSPEC |
+ IEEE80211_HW_SIGNAL_DBM))
+ wstats_flags |= IW_QUAL_LEVEL_UPDATED;
+ else
+ wstats_flags |= IW_QUAL_LEVEL_INVALID;
+
+ if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
+ wstats_flags |= IW_QUAL_NOISE_UPDATED;
+ else
+ wstats_flags |= IW_QUAL_NOISE_INVALID;
+
if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
wstats_flags |= IW_QUAL_DBM;
@@ -191,19 +199,11 @@ static int ieee80211_ioctl_giwrange(stru
if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
range->max_qual.level = 100;
else if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
- range->max_qual.level = -110;
- else
range->max_qual.level = 0;
- if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
- range->max_qual.noise = -110;
- else
- range->max_qual.noise = 0;
-
- range->max_qual.qual = 100;
+ range->max_qual.noise = 0;
range->max_qual.updated = ieee80211_get_wstats_flags(local);
- range->avg_qual.qual = 50;
/* not always true but better than nothing */
range->avg_qual.level = range->max_qual.level / 2;
range->avg_qual.noise = range->max_qual.noise / 2;
--
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