From: Christophe Leroy Date: Fri, 14 Sep 2018 10:32:50 +0000 (+0000) Subject: serial: cpm_uart: return immediately from console poll X-Git-Tag: v4.19~136^2~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=be28c1e3ca29887e207f0cbcd294cefe5074bab6;p=platform%2Fkernel%2Flinux-rpi.git serial: cpm_uart: return immediately from console poll kgdb expects poll function to return immediately and returning NO_POLL_CHAR when no character is available. Fixes: f5316b4aea024 ("kgdb,8250,pl011: Return immediately from console poll") Cc: Jason Wessel Cc: Signed-off-by: Christophe Leroy Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c index 24a5f05..e538959 100644 --- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c +++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c @@ -1054,8 +1054,8 @@ static int poll_wait_key(char *obuf, struct uart_cpm_port *pinfo) /* Get the address of the host memory buffer. */ bdp = pinfo->rx_cur; - while (bdp->cbd_sc & BD_SC_EMPTY) - ; + if (bdp->cbd_sc & BD_SC_EMPTY) + return NO_POLL_CHAR; /* If the buffer address is in the CPM DPRAM, don't * convert it. @@ -1090,7 +1090,11 @@ static int cpm_get_poll_char(struct uart_port *port) poll_chars = 0; } if (poll_chars <= 0) { - poll_chars = poll_wait_key(poll_buf, pinfo); + int ret = poll_wait_key(poll_buf, pinfo); + + if (ret == NO_POLL_CHAR) + return ret; + poll_chars = ret; pollp = poll_buf; } poll_chars--;