mxt_probe() may fail at last step, or we jsut unload mxt module soon.
the queue_work scheduled by request_firmware_nowait may run later,
and then access some data which is freed.
To handle this issue, add fw_load_completion field in mxt_data.
then we wait for it complete both in probe error path and mxt_remove().
here is the detail in probe, similar in remove.
module load:
worker_thread:
mxt_probe -> mxt_initialize -> request_firmware_nowait (schedule_work)
|
sysfs_create_group (fails)
mxt_config_cb -> mxt_configure_objects (may access data freed)
|
err_free_object: some cleanup work, like free(data).
Signed-off-by: xinhui.pan <xinhuix....@intel.com>
---
change in V2:
use fw_load_completion instead of statics.
fix a race both in mxt_remove and mxt_probe.
drivers/input/touchscreen/atmel_mxt_ts.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c
b/drivers/input/touchscreen/atmel_mxt_ts.c
index 40b98dd..3da040d 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -313,6 +313,9 @@ struct mxt_data {
/* for config update handling */
struct completion crc_completion;
+
+ /* for fw load handling */
+ struct completion fw_load_completion;
};
static size_t mxt_obj_size(const struct mxt_object *obj)
@@ -1982,8 +1985,10 @@ static int mxt_configure_objects(struct mxt_data *data,
static void mxt_config_cb(const struct firmware *cfg, void *ctx)
{
+ struct mxt_data *data = ctx;
mxt_configure_objects(ctx, cfg);
release_firmware(cfg);
+ complete(&data->fw_load_completion);
}
static int mxt_initialize(struct mxt_data *data)
@@ -2556,6 +2561,7 @@ static int mxt_probe(struct i2c_client *client, const
struct i2c_device_id *id)
init_completion(&data->bl_completion);
init_completion(&data->reset_completion);
init_completion(&data->crc_completion);
+ init_completion(&data->fw_load_completion);
error = request_threaded_irq(client->irq, NULL, mxt_interrupt,
pdata->irqflags | IRQF_ONESHOT,
@@ -2581,6 +2587,8 @@ static int mxt_probe(struct i2c_client *client, const
struct i2c_device_id *id)
return 0;
err_free_object:
+ mxt_wait_for_completion(data, &data->fw_load_completion,
+ MXT_FW_RESET_TIME);
mxt_free_input_device(data);
mxt_free_object_table(data);
err_free_irq:
@@ -2594,6 +2602,8 @@ static int mxt_remove(struct i2c_client *client)
{
struct mxt_data *data = i2c_get_clientdata(client);
+ mxt_wait_for_completion(data, &data->fw_load_completion,
+ MXT_FW_RESET_TIME);
sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
free_irq(data->irq, data);
mxt_free_input_device(data);
--
1.9.1
--
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