wifi: ath10k: Don't touch the CE interrupt registers after power up
authorDouglas Anderson <dianders@chromium.org>
Sat, 30 Sep 2023 04:54:48 +0000 (07:54 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 28 Nov 2023 17:06:56 +0000 (17:06 +0000)
commit459970363e7c9712f93eba66b51fd49bd464dbaf
tree3b81a04237fdb1800a4d4d422ef8bcb58d265a84
parent1c6a6c926abfd6be1cee613ef21a94ab8d253732
wifi: ath10k: Don't touch the CE interrupt registers after power up

[ Upstream commit 170c75d43a77dc937c58f07ecf847ba1b42ab74e ]

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@chromium.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230630151842.1.If764ede23c4e09a43a842771c2ddf99608f25f8e@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/wireless/ath/ath10k/snoc.c