From: Loic Poulain loic.poulain@linaro.org
commit 34737e1320db6d51f0d140d5c684b9eb32f0da76 upstream.
Lockdep detected possible interrupt unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(&mhiwwan->rx_lock); local_irq_disable(); lock(&mhi_cntrl->pm_lock); lock(&mhiwwan->rx_lock); <Interrupt> lock(&mhi_cntrl->pm_lock);
*** DEADLOCK ***
To prevent this we need to disable the soft-interrupts when taking the rx_lock.
Cc: stable@vger.kernel.org Fixes: fa588eba632d ("net: Add Qcom WWAN control driver") Reported-by: Thomas Perrot thomas.perrot@bootlin.com Signed-off-by: Loic Poulain loic.poulain@linaro.org Reviewed-by: Sergey Ryazanov ryazanov.s.a@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/wwan/mhi_wwan_ctrl.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/net/wwan/mhi_wwan_ctrl.c +++ b/drivers/net/wwan/mhi_wwan_ctrl.c @@ -41,14 +41,14 @@ struct mhi_wwan_dev { /* Increment RX budget and schedule RX refill if necessary */ static void mhi_wwan_rx_budget_inc(struct mhi_wwan_dev *mhiwwan) { - spin_lock(&mhiwwan->rx_lock); + spin_lock_bh(&mhiwwan->rx_lock);
mhiwwan->rx_budget++;
if (test_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags)) schedule_work(&mhiwwan->rx_refill);
- spin_unlock(&mhiwwan->rx_lock); + spin_unlock_bh(&mhiwwan->rx_lock); }
/* Decrement RX budget if non-zero and return true on success */ @@ -56,7 +56,7 @@ static bool mhi_wwan_rx_budget_dec(struc { bool ret = false;
- spin_lock(&mhiwwan->rx_lock); + spin_lock_bh(&mhiwwan->rx_lock);
if (mhiwwan->rx_budget) { mhiwwan->rx_budget--; @@ -64,7 +64,7 @@ static bool mhi_wwan_rx_budget_dec(struc ret = true; }
- spin_unlock(&mhiwwan->rx_lock); + spin_unlock_bh(&mhiwwan->rx_lock);
return ret; } @@ -130,9 +130,9 @@ static void mhi_wwan_ctrl_stop(struct ww { struct mhi_wwan_dev *mhiwwan = wwan_port_get_drvdata(port);
- spin_lock(&mhiwwan->rx_lock); + spin_lock_bh(&mhiwwan->rx_lock); clear_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags); - spin_unlock(&mhiwwan->rx_lock); + spin_unlock_bh(&mhiwwan->rx_lock);
cancel_work_sync(&mhiwwan->rx_refill);