Subject: [PATCH] Input: cyapa - do not call input_device_enabled from power mode handler

From: Dmitry Torokhov <[email-masked]>
Date: Thu, 10 Dec 2020 23:09:38 -0800

Input device's user counter is supposed to be accessed only while holding
input->mutex.  Commit d69f0a43c677 ("Input: use input_device_enabled()")
recently switched cyapa to using the dedicated API and it uncovered the
fact that cyapa driver violated this constraint.

This patch removes checks whether the input device is open when clearing
device queues when changing device's power mode as there is no harm in
sending input events through closed input device - the events will simply
be dropped by the input core.

Note that there are more places in cyapa driver that call
input_device_enabled() without holding input->mutex, those are left
unfixed for now.

Reported-by: Marek Szyprowski <[email-masked]>
Signed-off-by: Dmitry Torokhov <[email-masked]>
---

Marek, could you please try this one?

 drivers/input/mouse/cyapa_gen3.c |    5 +----
 drivers/input/mouse/cyapa_gen5.c |    3 +--
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/input/mouse/cyapa_gen3.c b/drivers/input/mouse/cyapa_gen3.c
index a97f4acb6452..4a9022faf945 100644
--- a/drivers/input/mouse/cyapa_gen3.c
+++ b/drivers/input/mouse/cyapa_gen3.c
@@ -907,7 +907,6 @@ static u16 cyapa_get_wait_time_for_pwr_cmd(u8 pwr_mode)
 static int cyapa_gen3_set_power_mode(struct cyapa *cyapa, u8 power_mode,
 		u16 always_unused, enum cyapa_pm_stage pm_stage)
 {
-	struct input_dev *input = cyapa->input;
 	u8 power;
 	int tries;
 	int sleep_time;
@@ -953,7 +952,6 @@ static int cyapa_gen3_set_power_mode(struct cyapa *cyapa, u8 power_mode,
 	 * depending on the command's content.
 	 */
 	if (cyapa->operational &&
-	    input && input_device_enabled(input) &&
 	    (pm_stage == CYAPA_PM_RUNTIME_SUSPEND ||
 	     pm_stage == CYAPA_PM_RUNTIME_RESUME)) {
 		/* Try to polling in 120Hz, read may fail, just ignore it. */
@@ -1223,8 +1221,7 @@ static int cyapa_gen3_try_poll_handler(struct cyapa *cyapa)
 	    (data.finger_btn & OP_DATA_VALID) != OP_DATA_VALID)
 		return -EINVAL;
 
-	return cyapa_gen3_event_process(cyapa, &data);
-
+	return cyapa->input ? cyapa_gen3_event_process(cyapa, &data) : 0;
 }
 
 static int cyapa_gen3_initialize(struct cyapa *cyapa) { return 0; }
diff --git a/drivers/input/mouse/cyapa_gen5.c b/drivers/input/mouse/cyapa_gen5.c
index abf42f77b4c5..afc5aa4dcf47 100644
--- a/drivers/input/mouse/cyapa_gen5.c
+++ b/drivers/input/mouse/cyapa_gen5.c
@@ -518,8 +518,7 @@ int cyapa_empty_pip_output_data(struct cyapa *cyapa,
 			*len = length;
 			/* Response found, success. */
 			return 0;
-		} else if (cyapa->operational &&
-			   input && input_device_enabled(input) &&
+		} else if (cyapa->operational && input &&
 			   (pm_stage == CYAPA_PM_RUNTIME_RESUME ||
 			    pm_stage == CYAPA_PM_RUNTIME_SUSPEND)) {
 			/* Parse the data and report it if it's valid. */

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