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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2023-05-11 11:52:45 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2023-05-18 11:40:32 -0700
commit7d674f9150c361e5b992551b46516d41eede3722 (patch)
treedbdf506fbd48d139cd86fa687481196d878f4b8c /drivers/input
parent1db0fd245b6016c21097b5ae01aeb447484de951 (diff)
Input: libps2 - fix aborting PS/2 commands
When aborting PS/2 command the kernel should [re]set all flags before waking up waiters, otherwise waiting thread may read obsolete values of flags. Reported-by: Raul Rangel <rrangel@chromium.org> Reviewed-by: Raul E Rangel <rrangel@chromium.org> Link: https://lore.kernel.org/r/20230511185252.386941-6-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
-rw-r--r--drivers/input/serio/libps2.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index 14b70a78875d..09eb605364bb 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -478,15 +478,22 @@ bool ps2_handle_response(struct ps2dev *ps2dev, u8 data)
}
EXPORT_SYMBOL(ps2_handle_response);
+/*
+ * Clears state of PS/2 device after communication error by resetting majority
+ * of flags and waking up waiters, if any.
+ */
void ps2_cmd_aborted(struct ps2dev *ps2dev)
{
- if (ps2dev->flags & PS2_FLAG_ACK)
+ unsigned long old_flags = ps2dev->flags;
+
+ /* reset all flags except last nak */
+ ps2dev->flags &= PS2_FLAG_NAK;
+
+ if (old_flags & PS2_FLAG_ACK)
ps2dev->nak = 1;
- if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
+ if (old_flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
wake_up(&ps2dev->wait);
- /* reset all flags except last nack */
- ps2dev->flags &= PS2_FLAG_NAK;
}
EXPORT_SYMBOL(ps2_cmd_aborted);