fw/sercomm: Additional locking needed in drv_pull

[osmocom-bb.git] / src / target / firmware / comm / sercomm.c

diff --git a/src/target/firmware/comm/sercomm.c b/src/target/firmware/comm/sercomm.c
index 8fa0347..ddc852c 100644 (file)
--- a/src/target/firmware/comm/sercomm.c
+++ b/src/target/firmware/comm/sercomm.c
@@ -147,9 +147,13 @@ unsigned int sercomm_tx_queue_depth(uint8_t dlci)
 /* fetch one octet of to-be-transmitted serial data */
 int sercomm_drv_pull(uint8_t *ch)
 {
-       /* we are always called from interrupt context in this function,
-        * which means that any data structures we use need to be for
-        * our exclusive access */
+       unsigned long flags;
+
+       /* we may be called from interrupt context, but we stiff need to lock
+        * because sercomm could be accessed from a FIQ context ... */
+
+       sercomm_lock(&flags);
+
        if (!sercomm.tx.msg) {
                unsigned int i;
                /* dequeue a new message from the queues */
@@ -162,9 +166,11 @@ int sercomm_drv_pull(uint8_t *ch)
                        /* start of a new message, send start flag octet */
                        *ch = HDLC_FLAG;
                        sercomm.tx.next_char = sercomm.tx.msg->data;
+                       sercomm_unlock(&flags);
                        return 1;
                } else {
                        /* no more data avilable */
+                       sercomm_unlock(&flags);
                        return 0;
                }
        }
@@ -195,6 +201,8 @@ int sercomm_drv_pull(uint8_t *ch)
                /* standard case, simply send next octet */
                *ch = *sercomm.tx.next_char++;
        }
+
+       sercomm_unlock(&flags);
        return 1;
 }