From 6c1f77c3781a893cabe04b560a63b0524fe458f3 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Tue, 3 May 2022 10:06:07 +0200 Subject: [PATCH] serial: pch: move size check from pop_tx one level up 'count' is zero in the pop_tx()'s comparison against 'size'. So the 'if' tries to find out if 'size' is negative or zero and returns in that case. But it cannot be negative, due to previous (size < 0) check in the caller: handle_tx(). So simply move this check from pop_tx() to handle_tx(). Now it's clear that pop_tx() is called only if fifo_size is non-zero. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220503080613.27601-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/pch_uart.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index affe71f8b50c..f872613a5e83 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -791,7 +791,7 @@ static int pop_tx(struct eg20t_port *priv, int size) struct uart_port *port = &priv->port; struct circ_buf *xmit = &port->state->xmit; - if (uart_tx_stopped(port) || uart_circ_empty(xmit) || count >= size) + if (uart_tx_stopped(port) || uart_circ_empty(xmit)) goto pop_tx_end; do { @@ -895,14 +895,16 @@ static unsigned int handle_tx(struct eg20t_port *priv) tx_empty = 0; fifo_size--; } + size = min(xmit->head - xmit->tail, fifo_size); if (size < 0) size = fifo_size; - - tx_size = pop_tx(priv, size); - if (tx_size > 0) { - port->icount.tx += tx_size; - tx_empty = 0; + if (size) { + tx_size = pop_tx(priv, size); + if (tx_size > 0) { + port->icount.tx += tx_size; + tx_empty = 0; + } } priv->tx_empty = tx_empty;