spi: spi-axi-spi-engine: setup the timer before IRQ enable

The watchdog timer was being activated after enabling the interrupts and
that could actually lead for the message to be transferred before we get
to call mod_timer() which would lead to a spurious soft interrupt. In
extreme cases (like playing with overlays to load + unload devices)
this could lead to a panic splat as the timer callback would be called
with the spi engine device gone already.

Fixes: fde5597 ("spi: axi-spi-engine: Add watchdog timer")
Signed-off-by: Nuno Sa <[email protected]>

drivers/spi/spi-axi-spi-engine.c

@@ -628,6 +628,8 @@ static int spi_engine_transfer_one_message(struct spi_master *master,
 		return -ENOMEM;
 	spi_engine_compile_message(spi_engine, msg, false, p);
 
+	mod_timer(&spi_engine->watchdog_timer, jiffies + 5 * HZ);
+
 	spin_lock_irqsave(&spi_engine->lock, flags);
 	spi_engine->sync_id = (spi_engine->sync_id + 1) & 0xff;
 	spi_engine_program_add_cmd(p, false,
@@ -656,8 +658,6 @@ static int spi_engine_transfer_one_message(struct spi_master *master,
 	spi_engine->int_enable = int_enable;
 	spin_unlock_irqrestore(&spi_engine->lock, flags);
 
-	mod_timer(&spi_engine->watchdog_timer, jiffies + 5*HZ);
-
 	return 0;
 }