move up ACK

Author: matteius

main.c

@@ -193,6 +193,8 @@ static void command_loop(void)
                 uint32_t rlen = 0;
                 readbytes_blocking(&rlen, 3);
 
+                sendbyte_blocking(S_ACK);
+
                 cs_select(SPI_CS);
 
                 while (wlen) {
@@ -202,8 +204,6 @@ static void command_loop(void)
                     wlen -= cur;
                 }
 
-                sendbyte_blocking(S_ACK);
-
                 while (rlen) {
                     uint32_t cur = MIN(rlen, sizeof buf);
                     spi_read_blocking(SPI_IF, 0, buf, cur);