Stanislaw Gruszka <sgruszka@xxxxxxxxxx> 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 <sgruszka@xxxxxxxxxx> Patch applied to ath-next branch of ath.git, thanks. b01c9e327249 ath9k: check ah->curchan when updating tx power -- https://patchwork.kernel.org/patch/9719543/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
