From 362014c8d9d51d504c167c44ac280169457732be Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Tue, 9 Feb 2016 01:02:38 +0300 Subject: [PATCH] xtensa: ISS: don't hang if stdin EOF is reached Simulator stdin may be connected to a file, when its end is reached kernel hangs in infinite loop inside rs_poll, because simc_poll always signals that descriptor 0 is readable and simc_read always returns 0. Check simc_read return value and exit loop if it's not positive. Also don't rewind polling timer if it's zero. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov --- arch/xtensa/platforms/iss/console.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/xtensa/platforms/iss/console.c b/arch/xtensa/platforms/iss/console.c index 70cb408bc20d..92d785fefb6d 100644 --- a/arch/xtensa/platforms/iss/console.c +++ b/arch/xtensa/platforms/iss/console.c @@ -100,21 +100,23 @@ static void rs_poll(unsigned long priv) { struct tty_port *port = (struct tty_port *)priv; int i = 0; + int rd = 1; unsigned char c; spin_lock(&timer_lock); while (simc_poll(0)) { - simc_read(0, &c, 1); + rd = simc_read(0, &c, 1); + if (rd <= 0) + break; tty_insert_flip_char(port, c, TTY_NORMAL); i++; } if (i) tty_flip_buffer_push(port); - - - mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); + if (rd) + mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); spin_unlock(&timer_lock); } -- 2.39.5