[Bug 242337] iwm - rate 0 causes iwm panic (and work around)

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242337

Mark Johnston <markj at FreeBSD.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |markj at FreeBSD.org

--- Comment #4 from Mark Johnston <markj at FreeBSD.org> ---
Hmm, note that one of the callers of iwm_rate2idx() already contains this logic
(i.e., maps an unknown rate to the lowest one).

I guess the problem is with the code which programs the fw rate table. 
iwm_setrates() already skips over invalid rates... but the code which fills in
the rest of the table is wrong.

Can you try this hack instead?  I did not test it.

There is a larger issue here in that we are ending up with a rate of 0, but we
can at least avoid panicking.

diff --git a/sys/dev/iwm/if_iwm.c b/sys/dev/iwm/if_iwm.c
index 06bd66cc3ef6..4bd6547cc57f 100644
--- a/sys/dev/iwm/if_iwm.c
+++ b/sys/dev/iwm/if_iwm.c
@@ -4385,8 +4385,10 @@ iwm_setrates(struct iwm_softc *sc, struct iwm_node *in,
int rix)

                /* Map 802.11 rate to HW rate index. */
                ridx = iwm_rate2ridx(sc, rate);
-               if (ridx == -1)
+               if (ridx == -1) {
+                       nrates--;
                        continue;
+               }

 #if 0
                if (txant == 0)

-- 
You are receiving this mail because:
You are the assignee for the bug.