From a3128feef6d516fecc33b6299266a4673454815f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 20 Jun 2018 21:36:47 +0200 Subject: libertas: use irqsave() in USB's complete callback The USB completion callback does not disable interrupts while acquiring the lock. We want to remove the local_irq_disable() invocation from __usb_hcd_giveback_urb() and therefore it is required for the callback handler to disable the interrupts while acquiring the lock. The callback may be invoked either in IRQ or BH context depending on the USB host controller. Use the _irqsave() variant of the locking primitives. I am removing the BUG_ON(!in_interrupt()); check because it serves no purpose. Running the completion callback in BH context makes in_interrupt() still return true but the interrupts could be enabled. The important part is that ->driver_lock is acquired with disabled interrupts which is the case now. Cc: Kalle Valo Cc: "David S. Miller" Cc: libertas-dev@lists.infradead.org Cc: linux-wireless@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Kalle Valo --- drivers/net/wireless/marvell/libertas/if_usb.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/marvell/libertas/if_usb.c b/drivers/net/wireless/marvell/libertas/if_usb.c index ffea610f67e2..c67a8e7be310 100644 --- a/drivers/net/wireless/marvell/libertas/if_usb.c +++ b/drivers/net/wireless/marvell/libertas/if_usb.c @@ -614,6 +614,7 @@ static inline void process_cmdrequest(int recvlength, uint8_t *recvbuff, struct if_usb_card *cardp, struct lbs_private *priv) { + unsigned long flags; u8 i; if (recvlength > LBS_CMD_BUFFER_SIZE) { @@ -623,9 +624,7 @@ static inline void process_cmdrequest(int recvlength, uint8_t *recvbuff, return; } - BUG_ON(!in_interrupt()); - - spin_lock(&priv->driver_lock); + spin_lock_irqsave(&priv->driver_lock, flags); i = (priv->resp_idx == 0) ? 1 : 0; BUG_ON(priv->resp_len[i]); @@ -635,7 +634,7 @@ static inline void process_cmdrequest(int recvlength, uint8_t *recvbuff, kfree_skb(skb); lbs_notify_command_response(priv, i); - spin_unlock(&priv->driver_lock); + spin_unlock_irqrestore(&priv->driver_lock, flags); lbs_deb_usbd(&cardp->udev->dev, "Wake up main thread to handle cmd response\n"); -- cgit