[PATCH AUTOSEL 4.19 031/146] wlcore: Fix BUG with clear completion on timeout

Sasha Levin
2018-10-31T23:52:13Z

From: Tony Lindgren <tony@atomide.com>

[ Upstream commit 4e651bad848955d88b29a568bfbfb4b831270e16 ]

We do not currently clear wl->elp_compl on ELP timeout and we have bogus
lingering pointer that wlcore_irq then will try to access after recovery
is done:

BUG: spinlock bad magic on CPU#1, irq/255-wl12xx/580
...
(spin_dump) from [<c01b9344>] (do_raw_spin_lock+0xc8/0x124)
(do_raw_spin_lock) from [<c09b3970>] (_raw_spin_lock_irqsave+0x68/0x74)
(_raw_spin_lock_irqsave) from [<c01a02f0>] (complete+0x24/0x58)
(complete) from [<bf572610>] (wlcore_irq+0x48/0x17c [wlcore])
(wlcore_irq [wlcore]) from [<c01c5efc>] (irq_thread_fn+0x2c/0x64)
(irq_thread_fn) from [<c01c623c>] (irq_thread+0x148/0x290)
(irq_thread) from [<c016b4b0>] (kthread+0x160/0x17c)
(kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20)
...

After that the system will hang. Let's fix this by adding a flag for
recovery and moving the recovery work call to to the error handling
section.

And we want to set WL1271_FLAG_INTENDED_FW_RECOVERY and actually clear
it too in wl1271_recovery_work() and just downgrade the error to a
warning to prevent overly verbose output.

Cc: Eyal Reizer <eyalr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ti/wlcore/main.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
index 89b0d0fade9f..19e3c5a0b715 100644
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -957,6 +957,8 @@ static void wl1271_recovery_work(struct work_struct *work)
BUG_ON(wl->conf.recovery.bug_on_recovery &&
!test_bit(WL1271_FLAG_INTENDED_FW_RECOVERY, &wl->flags));

+ clear_bit(WL1271_FLAG_INTENDED_FW_RECOVERY, &wl->flags);
+
if (wl->conf.recovery.no_recovery) {
wl1271_info("No recovery (chosen on module load). Fw will remain stuck.");
goto out_unlock;
@@ -6710,6 +6712,7 @@ static int __maybe_unused wlcore_runtime_resume(struct device *dev)
int ret;
unsigned long start_time = jiffies;
bool pending = false;
+ bool recovery = false;

/* Nothing to do if no ELP mode requested */
if (!test_bit(WL1271_FLAG_IN_ELP, &wl->flags))
@@ -6726,7 +6729,7 @@ static int __maybe_unused wlcore_runtime_resume(struct device *dev)

ret = wlcore_raw_write32(wl, HW_ACCESS_ELP_CTRL_REG, ELPCTRL_WAKE_UP);
if (ret < 0) {
- wl12xx_queue_recovery_work(wl);
+ recovery = true;
goto err;
}

@@ -6734,11 +6737,12 @@ static int __maybe_unused wlcore_runtime_resume(struct device *dev)
ret = wait_for_completion_timeout(&compl,
msecs_to_jiffies(WL1271_WAKEUP_TIMEOUT));
if (ret == 0) {
- wl1271_error("ELP wakeup timeout!");
- wl12xx_queue_recovery_work(wl);
+ wl1271_warning("ELP wakeup timeout!");

/* Return no error for runtime PM for recovery */
- return 0;
+ ret = 0;
+ recovery = true;
+ goto err;
}
}

@@ -6753,6 +6757,12 @@ static int __maybe_unused wlcore_runtime_resume(struct device *dev)
spin_lock_irqsave(&wl->wl_lock, flags);
wl->elp_compl = NULL;
spin_unlock_irqrestore(&wl->wl_lock, flags);
+
+ if (recovery) {
+ set_bit(WL1271_FLAG_INTENDED_FW_RECOVERY, &wl->flags);
+ wl12xx_queue_recovery_work(wl);
+ }
+
return ret;
}

--
2.17.1