ath10k_hw_qca988x_set_coverage_class needs to hold both conf_mutex and
the data_lock spin lock for parts of the function. However, data_lock
is only needed while storing the coverage_class to store the value that
the card is configured to.
Fix the locking issue by only holding data_lock for the required duration.
Signed-off-by: Benjamin Berg <benjamin@xxxxxxxxxxxxxxxx>
---
And yes, I fully agree with your points of it being rather fragile. But as
you said, it should be entirely safe if not used. Obviously a firmware
implementation would be preferential.
This locking issue was pretty unnecessary. Lets see if any more issues show
up in a closer review.
drivers/net/wireless/ath/ath10k/core.h | 2 +-
drivers/net/wireless/ath/ath10k/hw.c | 5 +++--
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index 89b07be..5f8c31f 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -915,7 +915,7 @@ struct ath10k {
struct work_struct set_coverage_class_work;
/* protected by conf_mutex */
struct {
- /* protected by data_lock */
+ /* writing also protected by data_lock */
s16 coverage_class;
u32 reg_phyclk;
diff --git a/drivers/net/wireless/ath/ath10k/hw.c b/drivers/net/wireless/ath/ath10k/hw.c
index e182f09..bd5ca6a 100644
--- a/drivers/net/wireless/ath/ath10k/hw.c
+++ b/drivers/net/wireless/ath/ath10k/hw.c
@@ -243,7 +243,6 @@ static void ath10k_hw_qca988x_set_coverage_class(struct ath10k *ar,
u32 fw_dbglog_level;
mutex_lock(&ar->conf_mutex);
- spin_lock_bh(&ar->data_lock);
/* Only modify registers if the core is started. */
if ((ar->state != ATH10K_STATE_ON) &&
@@ -356,12 +355,14 @@ static void ath10k_hw_qca988x_set_coverage_class(struct ath10k *ar,
store_regs:
/* After an error we will not retry setting the coverage class. */
+ spin_lock_bh(&ar->data_lock);
ar->fw_coverage.coverage_class = value;
+ spin_unlock_bh(&ar->data_lock);
+
ar->fw_coverage.reg_slottime_conf = slottime_reg;
ar->fw_coverage.reg_ack_cts_timeout_conf = timeout_reg;
unlock:
- spin_unlock_bh(&ar->data_lock);
mutex_unlock(&ar->conf_mutex);
}
--
2.9.3
