cpu/stm32/qdec: test null callback pointer (#14125)

cpu/stm32/qdec: test if callback pointer is set Callback pointer is not tested and could result in a hard fault if the pointer is NULL. Thus only activate interrupt if a callback provided. Signed-off-by: Gilles DOFFE <[email protected]>
RIOT-OS · Jul 10, 2020 · 8923701 · 8923701
1 parent 547a880
commit 8923701
Showing 1 changed file with 7 additions and 3 deletions.
diff --git a/cpu/stm32/periph/qdec.c b/cpu/stm32/periph/qdec.c
@@ -114,9 +114,13 @@ int32_t qdec_init(qdec_t qdec, qdec_mode_t mode, qdec_cb_t cb, void *arg)
     isr_ctx[qdec].cb = cb;
     isr_ctx[qdec].arg = arg;
 
-    /* Enable the qdec's interrupt */
-    NVIC_EnableIRQ(qdec_config[qdec].irqn);
-    dev(qdec)->DIER |= TIM_DIER_UIE;
+    /* Enable the qdec's interrupt only if there is a callback provided */
+    if (cb) {
+        NVIC_EnableIRQ(qdec_config[qdec].irqn);
+        dev(qdec)->DIER |= TIM_DIER_UIE;
+    } else {
+        dev(qdec)->DIER &= ~TIM_DIER_UIE;
+    }
 
     /* Reset counter and start qdec */
     qdec_start(qdec);