accel/qaic: Fix bootlog initialization ordering

As soon as we queue MHI buffers to receive the bootlog from the device,
we could be receiving data. Therefore all the resources needed to
process that data need to be setup prior to queuing the buffers.

We currently initialize some of the resources after queuing the buffers
which creates a race between the probe() and any data that comes back
from the device. If the uninitialized resources are accessed, we could
see page faults.

Fix the init ordering to close the race.

Fixes: 5f8df5c6def6 ("accel/qaic: Add bootlog debugfs")
Signed-off-by: Jeffrey Hugo <[e-mail]>
Signed-off-by: Youssef Samir <[e-mail]>
Reviewed-by: Jeff Hugo <[e-mail]>
Reviewed-by: Carl Vanderlip <[e-mail]>
Signed-off-by: Jeff Hugo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/accel/qaic/qaic_debugfs.c

···
 	if (ret)
 		goto destroy_workqueue;
 
+	dev_set_drvdata(&mhi_dev->dev, qdev);
+	qdev->bootlog_ch = mhi_dev;
+
 	for (i = 0; i < BOOTLOG_POOL_SIZE; i++) {
 		msg = devm_kzalloc(&qdev->pdev->dev, sizeof(*msg), GFP_KERNEL);
 		if (!msg) {
···
 			goto mhi_unprepare;
 	}
 
-	dev_set_drvdata(&mhi_dev->dev, qdev);
-	qdev->bootlog_ch = mhi_dev;
 	return 0;
 
 mhi_unprepare: