[sw, dif_uart] Remove incorrect NULL check in dif_uart_bytes_send
This function allows for bytes_written argument to be NULL, and hence
the check is incorrect.
This issue was discovered in a process of writing mock tests for DIF
UART.
Note: added a line to the function description of dif_uart_bytes_send,
and also dif_uart_bytes_receive.
Signed-off-by: Silvestrs Timofejevs <silvestrst@lowrisc.org>
diff --git a/sw/device/lib/dif/dif_uart.c b/sw/device/lib/dif/dif_uart.c
index e37a957..9bf1ed6 100644
--- a/sw/device/lib/dif/dif_uart.c
+++ b/sw/device/lib/dif/dif_uart.c
@@ -238,7 +238,7 @@
bool dif_uart_bytes_send(const dif_uart_t *uart, const uint8_t *data,
size_t bytes_requested, size_t *bytes_written) {
- if (uart == NULL || bytes_written == NULL) {
+ if (uart == NULL) {
return false;
}
diff --git a/sw/device/lib/dif/dif_uart.h b/sw/device/lib/dif/dif_uart.h
index 531f928..dcf12ee 100644
--- a/sw/device/lib/dif/dif_uart.h
+++ b/sw/device/lib/dif/dif_uart.h
@@ -142,7 +142,8 @@
*
* Non-blocking UART send bytes routine. Can be used from inside an UART ISR.
* This function attempts to write @p arg3 number of bytes to the UART TX FIFO
- * from @p arg3, and passes @p arg4 back to the caller.
+ * from @p arg3, and passes @p arg4 back to the caller. @p arg4 is optional,
+ * NULL should be passed in if the value is not needed.
*
* @param uart UART state data
* @param data Data to be written
@@ -158,7 +159,8 @@
*
* Non-blocking UART receive bytes routine. Can be used from inside an UART ISR.
* This function attempts to read @p arg2 number of bytes from the UART RX FIFO
- * into @p arg3, and passes @p arg4 back to the caller.
+ * into @p arg3, and passes @p arg4 back to the caller. @p arg4 is optional,
+ * NULL should be passed in if the value is not needed.
*
* @param uart UART state data
* @param bytes_requested Number of bytes requested to be read by the caller
