[PATCH 5.4 168/270] macintosh/via-macii: Access autopoll_devs when inside lock

From: Greg Kroah-Hartman
Date: Mon Aug 17 2020 - 14:14:36 EST


From: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 59ea38f6b3af5636edf541768a1ed721eeaca99e ]

The interrupt handler should be excluded when accessing the autopoll_devs
variable.

Fixes: d95fd5fce88f0 ("m68k: Mac II ADB fixes") # v5.0+
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Tested-by: Stan Johnson <userm57@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/5952dd8a9bc9de90f1acc4790c51dd42b4c98065.1593318192.git.fthain@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/macintosh/via-macii.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/macintosh/via-macii.c b/drivers/macintosh/via-macii.c
index ac824d7b2dcfc..6aa903529570d 100644
--- a/drivers/macintosh/via-macii.c
+++ b/drivers/macintosh/via-macii.c
@@ -270,15 +270,12 @@ static int macii_autopoll(int devs)
unsigned long flags;
int err = 0;

+ local_irq_save(flags);
+
/* bit 1 == device 1, and so on. */
autopoll_devs = devs & 0xFFFE;

- if (!autopoll_devs)
- return 0;
-
- local_irq_save(flags);
-
- if (current_req == NULL) {
+ if (autopoll_devs && !current_req) {
/* Send a Talk Reg 0. The controller will repeatedly transmit
* this as long as it is idle.
*/
--
2.25.1