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authorStefan Kerkmann <karlk90@pm.me>2022-06-21 00:24:53 +0200
committerGitHub <noreply@github.com>2022-06-21 08:24:53 +1000
commit2703ecc9e98819ab4d13bdb6da6e0d02ee840d86 (patch)
treea6ffe98a5dea71199255f23e612e469fa3bda3c0
parent62eaec52e0b6aadfea629e7457d1d7d8647e840c (diff)
[BUG] Fix deadlocks on disconnected secondary half (#17423)
-rw-r--r--platforms/chibios/drivers/serial.c11
-rw-r--r--platforms/chibios/drivers/serial_protocol.c8
-rw-r--r--platforms/synchronization_util.h30
3 files changed, 38 insertions, 11 deletions
diff --git a/platforms/chibios/drivers/serial.c b/platforms/chibios/drivers/serial.c
index e5f346ba33..3fae5cd3a4 100644
--- a/platforms/chibios/drivers/serial.c
+++ b/platforms/chibios/drivers/serial.c
@@ -87,10 +87,7 @@ static THD_FUNCTION(Thread1, arg) {
chRegSetThreadName("blinker");
while (true) {
palWaitLineTimeout(SOFT_SERIAL_PIN, TIME_INFINITE);
-
- split_shared_memory_lock();
interrupt_handler(NULL);
- split_shared_memory_unlock();
}
}
@@ -155,6 +152,7 @@ static void __attribute__((noinline)) serial_write_byte(uint8_t data) {
// interrupt handle to be used by the slave device
void interrupt_handler(void *arg) {
+ split_shared_memory_lock_autounlock();
chSysLockFromISR();
sync_send();
@@ -212,6 +210,8 @@ void interrupt_handler(void *arg) {
static inline bool initiate_transaction(uint8_t sstd_index) {
if (sstd_index > NUM_TOTAL_TRANSACTIONS) return false;
+ split_shared_memory_lock_autounlock();
+
split_transaction_desc_t *trans = &split_transaction_table[sstd_index];
// TODO: remove extra delay between transactions
@@ -292,8 +292,5 @@ static inline bool initiate_transaction(uint8_t sstd_index) {
//
// this code is very time dependent, so we need to disable interrupts
bool soft_serial_transaction(int sstd_index) {
- split_shared_memory_lock();
- bool result = initiate_transaction((uint8_t)sstd_index);
- split_shared_memory_unlock();
- return result;
+ return initiate_transaction((uint8_t)sstd_index);
}
diff --git a/platforms/chibios/drivers/serial_protocol.c b/platforms/chibios/drivers/serial_protocol.c
index 3e160e0c5c..c95aed9885 100644
--- a/platforms/chibios/drivers/serial_protocol.c
+++ b/platforms/chibios/drivers/serial_protocol.c
@@ -22,13 +22,11 @@ static THD_FUNCTION(SlaveThread, arg) {
chRegSetThreadName("split_protocol_tx_rx");
while (true) {
- split_shared_memory_lock();
if (unlikely(!react_to_transaction())) {
/* Clear the receive queue, to start with a clean slate.
* Parts of failed transactions or spurious bytes could still be in it. */
serial_transport_driver_clear();
}
- split_shared_memory_unlock();
}
}
@@ -64,6 +62,8 @@ static inline bool react_to_transaction(void) {
return false;
}
+ split_shared_memory_lock_autounlock();
+
split_transaction_desc_t* transaction = &split_transaction_table[transaction_id];
/* Send back the handshake which is XORed as a simple checksum,
@@ -102,9 +102,7 @@ static inline bool react_to_transaction(void) {
* @return bool Indicates success of transaction.
*/
bool soft_serial_transaction(int index) {
- split_shared_memory_lock();
bool result = initiate_transaction((uint8_t)index);
- split_shared_memory_unlock();
if (unlikely(!result)) {
/* Clear the receive queue, to start with a clean slate.
@@ -125,6 +123,8 @@ static inline bool initiate_transaction(uint8_t transaction_id) {
return false;
}
+ split_shared_memory_lock_autounlock();
+
split_transaction_desc_t* transaction = &split_transaction_table[transaction_id];
/* Send transaction table index to the slave, which doubles as basic handshake token. */
diff --git a/platforms/synchronization_util.h b/platforms/synchronization_util.h
index 3730f271db..81ce074cac 100644
--- a/platforms/synchronization_util.h
+++ b/platforms/synchronization_util.h
@@ -12,3 +12,33 @@ void split_shared_memory_unlock(void);
inline void split_shared_memory_lock(void){};
inline void split_shared_memory_unlock(void){};
#endif
+
+/* GCCs cleanup attribute expects a function with one parameter, which is a
+ * pointer to a type compatible with the variable. As we don't want to expose
+ * the platforms internal mutex type this workaround with auto generated adapter
+ * function is defined */
+#define QMK_DECLARE_AUTOUNLOCK_HELPERS(prefix) \
+ inline unsigned prefix##_autounlock_lock_helper(void) { \
+ prefix##_lock(); \
+ return 0; \
+ } \
+ \
+ inline void prefix##_autounlock_unlock_helper(unsigned* unused_guard) { \
+ prefix##_unlock(); \
+ }
+
+/* Convinience macro the automatically generate the correct RAII-style
+ * lock_autounlock function macro */
+#define QMK_DECLARE_AUTOUNLOCK_CALL(prefix) unsigned prefix##_guard __attribute__((unused, cleanup(prefix##_autounlock_unlock_helper))) = prefix##_autounlock_lock_helper
+
+QMK_DECLARE_AUTOUNLOCK_HELPERS(split_shared_memory)
+
+/**
+ * @brief Acquire exclusive access to the split keyboard shared memory, by
+ * calling the platforms `split_shared_memory_lock()` function. The lock is
+ * automatically released by calling the platforms `split_shared_memory_unlock()`
+ * function. This happens when the block where
+ * `split_shared_memory_lock_autounlock()` is called in goes out of scope i.e.
+ * when the enclosing function returns.
+ */
+#define split_shared_memory_lock_autounlock QMK_DECLARE_AUTOUNLOCK_CALL(split_shared_memory)