RE: [PATCH 06/10] cfg80211: honor NL80211_RRF_NO_HT40{MINUS,PLUS}

[Grumbach, Emmanuel]

> 
> On Tue, 2017-09-05 at 16:49 +, Grumbach, Emmanuel wrote:
> > On Tue, 2017-09-05 at 16:30 +0200, Johannes Berg wrote:
> > > On Sat, 2017-08-05 at 11:44 +0300, Luca Coelho wrote:
> > >
> > > > +   regd = get_wiphy_regdom(wiphy);
> > > > +   if (regd) {
> > > > +   const struct ieee80211_reg_rule *reg_rule =
> > > > +   freq_reg_info_regd(MHZ_TO_KHZ(channel-
> > > > > center_freq),
> > > >
> > > > +      regd,
> > > > MHZ_TO_KHZ(20));
> > > >
> > >
> > > This could return an error, how can you be sure it doesn't?
> > >
> >
> > Hm... so I guess I could check that it didn't return any error and if
> > it did, then flags = 0?
> >
> > Something like this? (on top of this patch):
> > [snip]
> 
> yeah that's obviously the easy thing to do - I just wasn't sure that you 
> didn't
> have a reason to believe it could never be an ERR_PTR :)
>
TBH, I don't really know... I don't know if *all* the channels are covered by 
rules.
For sure, if there is no rule, I can assume that the HT40{+,-} are not set... 
But I don't know if that's even possible.

Re: [PATCH 06/10] cfg80211: honor NL80211_RRF_NO_HT40{MINUS,PLUS}

[Johannes Berg]

On Tue, 2017-09-05 at 16:49 +, Grumbach, Emmanuel wrote:
> On Tue, 2017-09-05 at 16:30 +0200, Johannes Berg wrote:
> > On Sat, 2017-08-05 at 11:44 +0300, Luca Coelho wrote:
> > 
> > > + regd = get_wiphy_regdom(wiphy);
> > > + if (regd) {
> > > + const struct ieee80211_reg_rule *reg_rule =
> > > + freq_reg_info_regd(MHZ_TO_KHZ(channel-
> > > > center_freq),
> > > 
> > > +    regd,
> > > MHZ_TO_KHZ(20));
> > > 
> > 
> > This could return an error, how can you be sure it doesn't?
> > 
> 
> Hm... so I guess I could check that it didn't return any error and if
> it did, then flags = 0?
> 
> Something like this? (on top of this patch):
> [snip]

yeah that's obviously the easy thing to do - I just wasn't sure that
you didn't have a reason to believe it could never be an ERR_PTR :)

johannes

[PATCH 06/10] cfg80211: honor NL80211_RRF_NO_HT40{MINUS,PLUS}

[Luca Coelho]

From: Emmanuel Grumbach 

Honor the NL80211_RRF_NO_HT40{MINUS,PLUS} flags in
reg_process_ht_flags_channel. Not doing so leads can lead
to a firmware assert in iwlwifi for example.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=195299

Fixes: b0d7aa59592b ("cfg80211: allow wiphy specific regdomain management")
Signed-off-by: Emmanuel Grumbach 
Signed-off-by: Luca Coelho 
---
 net/wireless/reg.c | 20 ++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 5fae296a6a58..29879440626e 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -4,6 +4,7 @@
  * Copyright 2007  Johannes Berg 
  * Copyright 2008-2011 Luis R. Rodriguez 
  * Copyright 2013-2014  Intel Mobile Communications GmbH
+ * Copyright  2017  Intel Deutschland GmbH
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -1483,7 +1484,9 @@ static void reg_process_ht_flags_channel(struct wiphy 
*wiphy,
 {
struct ieee80211_supported_band *sband = wiphy->bands[channel->band];
struct ieee80211_channel *channel_before = NULL, *channel_after = NULL;
+   const struct ieee80211_regdomain *regd;
unsigned int i;
+   u32 flags;
 
if (!is_ht40_allowed(channel)) {
channel->flags |= IEEE80211_CHAN_NO_HT40;
@@ -1503,17 +1506,30 @@ static void reg_process_ht_flags_channel(struct wiphy 
*wiphy,
channel_after = c;
}
 
+   regd = get_wiphy_regdom(wiphy);
+   if (regd) {
+   const struct ieee80211_reg_rule *reg_rule =
+   freq_reg_info_regd(MHZ_TO_KHZ(channel->center_freq),
+  regd, MHZ_TO_KHZ(20));
+
+   flags = reg_rule->flags;
+   } else {
+   flags = 0;
+   }
+
/*
 * Please note that this assumes target bandwidth is 20 MHz,
 * if that ever changes we also need to change the below logic
 * to include that as well.
 */
-   if (!is_ht40_allowed(channel_before))
+   if (!is_ht40_allowed(channel_before) ||
+   flags & NL80211_RRF_NO_HT40MINUS)
channel->flags |= IEEE80211_CHAN_NO_HT40MINUS;
else
channel->flags &= ~IEEE80211_CHAN_NO_HT40MINUS;
 
-   if (!is_ht40_allowed(channel_after))
+   if (!is_ht40_allowed(channel_after) ||
+   flags & NL80211_RRF_NO_HT40PLUS)
channel->flags |= IEEE80211_CHAN_NO_HT40PLUS;
else
channel->flags &= ~IEEE80211_CHAN_NO_HT40PLUS;
-- 
2.13.2