Re: [PATCH u-boot-marvell 2/5] tools: kwboot: Do not call tcdrain() after each sent packet

On 27.10.21 20:56, Marek Behún wrote:

From: Pali Rohár pali@kernel.org

Kwboot puts each xmodem packet to kernel queue, then waits until all bytes of that packet are transmitted over UART and then waits for xmodem reply until it is received into kernel queue.

If some reply is received during the time we are waiting until all bytes are transmitted, then kernel puts them into the queue and returns it to kwboot in next read() call.

So there is no need to wait (with tcdrain() function) until all bytes from xmodem packet are transmitted over UART, since any reply received either during that time or after is returned to kwboot with the next read().

Therefore do not call tcdrain() after each xmodem packet sent. Instead directly wait for any reply after putting xmodem packet into write kernel queue.

This change could speed up xmodem transfer in case tcdrain() function waits for a longer time.

Signed-off-by: Pali Rohár pali@kernel.org Reviewed-by: Marek Behún marek.behun@nic.cz

Reviewed-by: Stefan Roese sr@denx.de

Thanks, Stefan

---

tools/kwboot.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/tools/kwboot.c b/tools/kwboot.c index b2c48812c3..a6bfd3d4ce 100644 --- a/tools/kwboot.c +++ b/tools/kwboot.c @@ -404,7 +404,7 @@ out: }

static int -kwboot_tty_send(int fd, const void *buf, size_t len) +kwboot_tty_send(int fd, const void *buf, size_t len, int nodrain) { if (!buf) return 0; @@ -412,13 +412,16 @@ kwboot_tty_send(int fd, const void *buf, size_t len) if (kwboot_write(fd, buf, len) < 0) return -1;

• if (nodrain)

• return 0;
  

• return tcdrain(fd); }

  static int kwboot_tty_send_char(int fd, unsigned char c) {

• return kwboot_tty_send(fd, &c, 1);

• return kwboot_tty_send(fd, &c, 1, 0); }

  static speed_t

@@ -705,7 +708,7 @@ kwboot_bootmsg(int tty, void *msg) break;

for (count = 0; count < 128; count++) {

• 	rc = kwboot_tty_send(tty, msg, 8);
  

• 	rc = kwboot_tty_send(tty, msg, 8, 0);
  if (rc) {
  	usleep(msg_req_delay * 1000);
  	continue;
  

@@ -737,7 +740,7 @@ kwboot_debugmsg(int tty, void *msg) if (rc) break;

• rc = kwboot_tty_send(tty, msg, 8);
  

• rc = kwboot_tty_send(tty, msg, 8, 0);
  

  if (rc) { usleep(msg_req_delay * 1000); continue;

@@ -929,7 +932,7 @@ kwboot_xm_sendblock(int fd, struct kwboot_block *block, int allow_non_xm,

retries = 0; do {

• rc = kwboot_tty_send(fd, block, sizeof(*block));
  

• rc = kwboot_tty_send(fd, block, sizeof(*block), 1);
  

  if (rc) return rc;

Viele Grüße, Stefan