modem: cmux: make work buffer size configurable

A Kconfig item is added and the buffer is embedded into the modem_cmux struct. The default value is increased from 16 to 64 bytes in an effort to reduce the number of modem_pipe_receive() calls. CONFIG_MODEM_CHAT_LOG_BUFFER is renamed to CONFIG_MODEM_CHAT_LOG_BUFFER_SIZE for consistency. Signed-off-by: Tomi Fontanilles <tomi.fontanilles@nordicsemi.no>
swkim101 · Mar 26, 2024 · 18170eb · 18170eb
1 parent 419a398
commit 18170eb
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Showing 5 changed files with 19 additions and 7 deletions.
diff --git a/doc/releases/migration-guide-3.7.rst b/doc/releases/migration-guide-3.7.rst
@@ -188,6 +188,12 @@ LoRaWAN
 MCUmgr
 ======
 
+Modem
+=====
+
+* The ``CONFIG_MODEM_CHAT_LOG_BUFFER`` Kconfig option was
+  renamed to :kconfig:option:`MODEM_CHAT_LOG_BUFFER_SIZE`.
+
 Shell
 =====
 

diff --git a/include/zephyr/modem/cmux.h b/include/zephyr/modem/cmux.h
@@ -141,6 +141,8 @@ struct modem_cmux {
 	uint16_t receive_buf_size;
 	uint16_t receive_buf_len;
 
+	uint8_t work_buf[CONFIG_MODEM_CMUX_WORK_BUFFER_SIZE];
+
 	/* Transmit buffer */
 	struct ring_buf transmit_rb;
 	struct k_mutex transmit_rb_lock;

diff --git a/subsys/modem/Kconfig b/subsys/modem/Kconfig
@@ -14,8 +14,8 @@ config MODEM_CHAT
 
 if MODEM_CHAT
 
-config MODEM_CHAT_LOG_BUFFER
-	int "Modem chat log buffer size"
+config MODEM_CHAT_LOG_BUFFER_SIZE
+	int "Modem chat log buffer size in bytes"
 	default 128
 
 endif
@@ -29,6 +29,11 @@ config MODEM_CMUX
 
 if MODEM_CMUX
 
+config MODEM_CMUX_WORK_BUFFER_SIZE
+	int "CMUX module work buffer size in bytes"
+	range 16 1500
+	default 64
+
 module = MODEM_CMUX
 module-str = modem_cmux
 source "subsys/logging/Kconfig.template.log_config"

diff --git a/subsys/modem/modem_chat.c b/subsys/modem/modem_chat.c
@@ -20,7 +20,7 @@ LOG_MODULE_REGISTER(modem_chat, CONFIG_MODEM_MODULES_LOG_LEVEL);
 
 #if defined(CONFIG_LOG) && (CONFIG_MODEM_MODULES_LOG_LEVEL == LOG_LEVEL_DBG)
 
-static char log_buffer[CONFIG_MODEM_CHAT_LOG_BUFFER];
+static char log_buffer[CONFIG_MODEM_CHAT_LOG_BUFFER_SIZE];
 
 static void modem_chat_log_received_command(struct modem_chat *chat)
 {

diff --git a/subsys/modem/modem_cmux.c b/subsys/modem/modem_cmux.c
@@ -842,11 +842,10 @@ static void modem_cmux_receive_handler(struct k_work *item)
 {
 	struct k_work_delayable *dwork = k_work_delayable_from_work(item);
 	struct modem_cmux *cmux = CONTAINER_OF(dwork, struct modem_cmux, receive_work);
-	uint8_t buf[16];
 	int ret;
 
 	/* Receive data from pipe */
-	ret = modem_pipe_receive(cmux->pipe, buf, sizeof(buf));
+	ret = modem_pipe_receive(cmux->pipe, cmux->work_buf, sizeof(cmux->work_buf));
 	if (ret < 1) {
 		if (ret < 0) {
 			LOG_ERR("Pipe receiving error: %d", ret);
@@ -855,8 +854,8 @@ static void modem_cmux_receive_handler(struct k_work *item)
 	}
 
 	/* Process received data */
-	for (uint16_t i = 0; i < (uint16_t)ret; i++) {
-		modem_cmux_process_received_byte(cmux, buf[i]);
+	for (int i = 0; i < ret; i++) {
+		modem_cmux_process_received_byte(cmux, cmux->work_buf[i]);
 	}
 
 	/* Reschedule received work */