[PATCH] ath10k: Don't touch the CE interrupt registers after power up

[Kalle Valo]

Douglas Anderson <dianders at chromium.org> wrote:

> As talked about in commit d66d24ac300c ("ath10k: Keep track of which
> interrupts fired, don't poll them"), if we access the copy engine
> register at a bad time then ath10k can go boom. However, it's not
> necessarily easy to know when it's safe to access them.
> 
> The ChromeOS test labs saw a crash that looked like this at
> shutdown/reboot time (on a chromeos-5.15 kernel, but likely the
> problem could also reproduce upstream):
> 
> Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP
> ...
> CPU: 4 PID: 6168 Comm: reboot Not tainted 5.15.111-lockdep-19350-g1d624fe6758f #1 010b9b233ab055c27c6dc88efb0be2f4e9e86f51
> Hardware name: Google Kingoftown (DT)
> ...
> pc : ath10k_snoc_read32+0x50/0x74 [ath10k_snoc]
> lr : ath10k_snoc_read32+0x24/0x74 [ath10k_snoc]
> ...
> Call trace:
> ath10k_snoc_read32+0x50/0x74 [ath10k_snoc ...]
> ath10k_ce_disable_interrupt+0x190/0x65c [ath10k_core ...]
> ath10k_ce_disable_interrupts+0x8c/0x120 [ath10k_core ...]
> ath10k_snoc_hif_stop+0x78/0x660 [ath10k_snoc ...]
> ath10k_core_stop+0x13c/0x1ec [ath10k_core ...]
> ath10k_halt+0x398/0x5b0 [ath10k_core ...]
> ath10k_stop+0xfc/0x1a8 [ath10k_core ...]
> drv_stop+0x148/0x6b4 [mac80211 ...]
> ieee80211_stop_device+0x70/0x80 [mac80211 ...]
> ieee80211_do_stop+0x10d8/0x15b0 [mac80211 ...]
> ieee80211_stop+0x144/0x1a0 [mac80211 ...]
> __dev_close_many+0x1e8/0x2c0
> dev_close_many+0x198/0x33c
> dev_close+0x140/0x210
> cfg80211_shutdown_all_interfaces+0xc8/0x1e0 [cfg80211 ...]
> ieee80211_remove_interfaces+0x118/0x5c4 [mac80211 ...]
> ieee80211_unregister_hw+0x64/0x1f4 [mac80211 ...]
> ath10k_mac_unregister+0x4c/0xf0 [ath10k_core ...]
> ath10k_core_unregister+0x80/0xb0 [ath10k_core ...]
> ath10k_snoc_free_resources+0xb8/0x1ec [ath10k_snoc ...]
> ath10k_snoc_shutdown+0x98/0xd0 [ath10k_snoc ...]
> platform_shutdown+0x7c/0xa0
> device_shutdown+0x3e0/0x58c
> kernel_restart_prepare+0x68/0xa0
> kernel_restart+0x28/0x7c
> 
> Though there's no known way to reproduce the problem, it makes sense
> that it would be the same issue where we're trying to access copy
> engine registers when it's not allowed.
> 
> Let's fix this by changing how we "disable" the interrupts. Instead of
> tweaking the copy engine registers we'll just use disable_irq() and
> enable_irq(). Then we'll configure the interrupts once at power up
> time.
> 
> Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.2.2.c10-00754-QCAHLSWMTPL-1
> 
> Signed-off-by: Douglas Anderson <dianders at chromium.org>
> Signed-off-by: Kalle Valo <quic_kvalo at quicinc.com>

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

170c75d43a77 wifi: ath10k: Don't touch the CE interrupt registers after power up

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20230630151842.1.If764ede23c4e09a43a842771c2ddf99608f25f8e@changeid/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches