On Tue, Jan 07, 2025 at 10:32:58PM +0106, John Ogness wrote:

Rather than using a hard-coded per-character Tx-timeout of 10ms,
use the frame time to determine a timeout value. The value is
doubled to ensure that a timeout is only hit during unexpected
circumstances.

Since the frame time may not be available during early printing,
the previous 10ms value is kept as a fallback.

...

+	/*
+	 * Wait for a character to be sent. Fallback to a safe default
+	 * timeout value if @frame_time is not available.
+	 */
+	if (up->port.frame_time)
+		tmout = up->port.frame_time * 2 / NSEC_PER_USEC;
+	else
+		tmout = 10000;

I would use it in a form of

		tmout = 10 * USEC_PER_MSEC;

This will give a hint of the real unit (10 ms in us).

-- 
With Best Regards,
Andy Shevchenko