Messages in this thread | | | Date | Wed, 30 Sep 2020 22:07:12 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH 4.19 144/245] serial: uartps: Wait for tx_empty in console setup |
| |
Hi!
> From: Raviteja Narayanam <raviteja.narayanam@xilinx.com> > > [ Upstream commit 42e11948ddf68b9f799cad8c0ddeab0a39da33e8 ] > > On some platforms, the log is corrupted while console is being > registered. It is observed that when set_termios is called, there > are still some bytes in the FIFO to be transmitted. > > So, wait for tx_empty inside cdns_uart_console_setup before calling > set_termios.
> @@ -1246,6 +1247,13 @@ static int cdns_uart_console_setup(struct console *co, char *options) > if (options) > uart_parse_options(options, &baud, &parity, &bits, &flow); > > + /* Wait for tx_empty before setting up the console */ > + time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT); > + > + while (time_before(jiffies, time_out) && > + cdns_uart_tx_empty(port) != TIOCSER_TEMT) > + cpu_relax(); > +
So this is spinning for half a second. Could we use msleep(1) instead of cpu_relax or something like that?
Best regards, Pavel
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html [unhandled content-type:application/pgp-signature] | |