X-Git-Url: https://git.friedersdorff.com/?a=blobdiff_plain;f=tmk_core%2Fcommon%2Favr%2Fuart.c;h=0fec705f9e3b230b5992c4eeb1e11618ef4140c9;hb=47775af20671e347e7e5545f63b42a51f0a4df04;hp=d9d42390230be79192e175511c6fb98fc664b7ef;hpb=c41e48a0ab0712d2667feb6b5dd8a4d5491cfcc5;p=max%2Ftmk_keyboard.git

diff --git a/tmk_core/common/avr/uart.c b/tmk_core/common/avr/uart.c
index d9d42390..0fec705f 100644
--- a/tmk_core/common/avr/uart.c
+++ b/tmk_core/common/avr/uart.c
@@ -66,7 +66,7 @@
 
 // These buffers may be any size from 2 to 256 bytes.
 #define RX_BUFFER_SIZE 64
-#define TX_BUFFER_SIZE 40
+#define TX_BUFFER_SIZE 256
 
 static volatile uint8_t tx_buffer[TX_BUFFER_SIZE];
 static volatile uint8_t tx_buffer_head;
@@ -95,6 +95,8 @@ void uart_putchar(uint8_t c)
 
 	i = tx_buffer_head + 1;
 	if (i >= TX_BUFFER_SIZE) i = 0;
+	// return immediately to avoid deadlock when interrupt is disabled(called from ISR)
+	if (tx_buffer_tail == i && (SREG & (1<<SREG_I)) == 0) return;
 	while (tx_buffer_tail == i) ; // wait until space in buffer
 	//cli();
 	tx_buffer[i] = c;