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authorStanislaw Gruszka <sgruszka@redhat.com>2017-05-10 11:54:54 +0300
committerKalle Valo <kvalo@qca.qualcomm.com>2017-05-19 10:59:31 +0300
commitb01c9e327249e4995e5b5b6cebec14166db9c1e7 (patch)
tree2227898336898639c1c4561679a22c2a76ff8fb7 /drivers/net/wireless
parent641c1f4ab7f62278a3a08c0861725ba21a53e5d5 (diff)
downloadlinux-b01c9e327249e4995e5b5b6cebec14166db9c1e7.tar.xz
ath9k: check ah->curchan when updating tx power
When driver fail to reset card ah->curchan value stay NULL. When later driver try to update tx power it oops by using ah->curchan (calltrace is shown below). This problem were reported at various places and for some it was fixed by making ath9k_hw_chip_reset() do not fail. I have this bug report on some oldish RHEL kernel with AR9285, however it's hard to debug where reset fail when kernel OOPS, so I think this patch should be applied. Hopefully ah->curchan is not used unconditionally on other places until is initialized on ath9k_config(). ath: phy0: Chip reset failed ath: phy0: Unable to reset hardware; reset status -22 (freq 2412 MHz) BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<f8a35585>] ath9k_hw_set_txpowerlimit+0x25/0x80 [ath9k_hw] Oops: 0000 [#1] SMP <snip> Call Trace: [<f8aac1aa>] ? ath9k_cmn_update_txpow+0x1a/0x30 [ath9k_common] [<f8cf4f4e>] ? ath_complete_reset+0x4e/0x130 [ath9k] [<f8cf54d7>] ? ath9k_start+0x127/0x1e0 [ath9k] [<f8c2e52f>] ? ieee80211_do_open+0x30f/0x910 [mac80211] [<c07bd96d>] ? dev_open+0x8d/0xf0 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Diffstat (limited to 'drivers/net/wireless')
-rw-r--r--drivers/net/wireless/ath/ath9k/common.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
index b80e08b13b74..eea2f7f23a2a 100644
--- a/drivers/net/wireless/ath/ath9k/common.c
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -368,7 +368,7 @@ void ath9k_cmn_update_txpow(struct ath_hw *ah, u16 cur_txpow,
{
struct ath_regulatory *reg = ath9k_hw_regulatory(ah);
- if (reg->power_limit != new_txpow)
+ if (ah->curchan && reg->power_limit != new_txpow)
ath9k_hw_set_txpowerlimit(ah, new_txpow, false);
/* read back in case value is clamped */