[PATCH 4.9 48/51] btmrvl: avoid double-disable_irq() race

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>


[ Upstream commit 9af02d86e11dc409e5c3de46e81c0a492ba58905 ]

It's much the same as what we did for mwifiex in:
b9da4d2 mwifiex: avoid double-disable_irq() race

"We have a race where the wakeup IRQ might be in flight while we're
calling mwifiex_disable_wake() from resume(). This can leave us
disabling the IRQ twice.

Let's disable the IRQ and enable it in case if we have double-disabled
it."

Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/bluetooth/btmrvl_sdio.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/bluetooth/btmrvl_sdio.c
+++ b/drivers/bluetooth/btmrvl_sdio.c
@@ -1682,8 +1682,12 @@ static int btmrvl_sdio_resume(struct dev
 	/* Disable platform specific wakeup interrupt */
 	if (card->plt_wake_cfg && card->plt_wake_cfg->irq_bt >= 0) {
 		disable_irq_wake(card->plt_wake_cfg->irq_bt);
-		if (!card->plt_wake_cfg->wake_by_bt)
-			disable_irq(card->plt_wake_cfg->irq_bt);
+		disable_irq(card->plt_wake_cfg->irq_bt);
+		if (card->plt_wake_cfg->wake_by_bt)
+			/* Undo our disable, since interrupt handler already
+			 * did this.
+			 */
+			enable_irq(card->plt_wake_cfg->irq_bt);
 	}
 
 	return 0;