2013-10-02 09:51:14

by Michal Kazior

Subject: [PATCH] ath10k: fix scheduling while atomic bug on config

Recent WMI/HTC changes introduces this bug because
now WMI commands can sleep.

Use appropriate interface iteration function.

Reported-By: Kalle Valo <[email protected]>
Signed-off-by: Michal Kazior <[email protected]>
---
drivers/net/wireless/ath/ath10k/mac.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 8684e03..b65df84 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -1935,9 +1935,8 @@ static void ath10k_config_ps(struct ath10k *ar)
memset(&ar_iter, 0, sizeof(struct ath10k_generic_iter));
ar_iter.ar = ar;

- ieee80211_iterate_active_interfaces_atomic(
- ar->hw, IEEE80211_IFACE_ITER_NORMAL,
- ath10k_ps_iter, &ar_iter);
+ ieee80211_iterate_active_interfaces(ar->hw, IEEE80211_IFACE_ITER_NORMAL,
+ ath10k_ps_iter, &ar_iter);

if (ar_iter.ret)
ath10k_warn("failed to set ps config (%d)\n", ar_iter.ret);
@@ -2840,9 +2839,8 @@ static int ath10k_set_rts_threshold(struct ieee80211_hw *hw, u32 value)
ar_iter.ar = ar;

mutex_lock(&ar->conf_mutex);
- ieee80211_iterate_active_interfaces_atomic(
- hw, IEEE80211_IFACE_ITER_NORMAL,
- ath10k_set_rts_iter, &ar_iter);
+ ieee80211_iterate_active_interfaces(hw, IEEE80211_IFACE_ITER_NORMAL,
+ ath10k_set_rts_iter, &ar_iter);
mutex_unlock(&ar->conf_mutex);

return ar_iter.ret;
@@ -2881,9 +2879,8 @@ static int ath10k_set_frag_threshold(struct ieee80211_hw *hw, u32 value)
ar_iter.ar = ar;

mutex_lock(&ar->conf_mutex);
- ieee80211_iterate_active_interfaces_atomic(
- hw, IEEE80211_IFACE_ITER_NORMAL,
- ath10k_set_frag_iter, &ar_iter);
+ ieee80211_iterate_active_interfaces(hw, IEEE80211_IFACE_ITER_NORMAL,
+ ath10k_set_frag_iter, &ar_iter);
mutex_unlock(&ar->conf_mutex);

return ar_iter.ret;
--
1.7.9.5

2013-10-02 13:00:36

by Kalle Valo

Subject: Re: [PATCH] ath10k: fix scheduling while atomic bug on config

Michal Kazior <[email protected]> writes:

> On 2 October 2013 11:51, Michal Kazior <[email protected]> wrote:
>> Recent WMI/HTC changes introduces this bug because
>> now WMI commands can sleep.
>>
>> Use appropriate interface iteration function.
>>
>> Reported-By: Kalle Valo <[email protected]>
>> Signed-off-by: Michal Kazior <[email protected]>
>
> Self NACK.
>
> I've posted this too soon. This patch can lead to deadlocks on
> iflist_mtx in some cases.

Ok, thanks for letting me know. I'll drop the patch from my queue.

--
Kalle Valo

2013-10-02 11:18:13

by Michal Kazior

Subject: Re: [PATCH] ath10k: fix scheduling while atomic bug on config

On 2 October 2013 11:51, Michal Kazior <[email protected]> wrote:
> Recent WMI/HTC changes introduces this bug because
> now WMI commands can sleep.
>
> Use appropriate interface iteration function.
>
> Reported-By: Kalle Valo <[email protected]>
> Signed-off-by: Michal Kazior <[email protected]>

Self NACK.

I've posted this too soon. This patch can lead to deadlocks on
iflist_mtx in some cases.


Michał