Stanislaw Gruszka <> wrote:
> 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 <>

Patch applied to ath-next branch of ath.git, thanks.

b01c9e327249 ath9k: check ah->curchan when updating tx power


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