From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932724Ab2DXWhZ (ORCPT ); Tue, 24 Apr 2012 18:37:25 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:38637 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932686Ab2DXWhT (ORCPT ); Tue, 24 Apr 2012 18:37:19 -0400 Message-Id: <20120424223253.891798385@linuxfoundation.org> User-Agent: quilt/0.60-19.1 Date: Tue, 24 Apr 2012 15:32:58 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alexander Shiyan Subject: [ 05/42] ARM: clps711x: serial driver hungs are a result of call disable_irq within ISR In-Reply-To: <20120424223311.GA8456@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Shiyan commit 7a6fbc9a887193a1e9f8658703881c528040afbc upstream. Since 2.6.30-rc1 clps711x serial driver hungs system. This is a result of call disable_irq from ISR. synchronize_irq waits for end of interrupt and goes to infinite loop. This patch fix this problem. Signed-off-by: Alexander Shiyan Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/clps711x.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/tty/serial/clps711x.c +++ b/drivers/tty/serial/clps711x.c @@ -154,10 +154,9 @@ static irqreturn_t clps711xuart_int_tx(i port->x_char = 0; return IRQ_HANDLED; } - if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { - clps711xuart_stop_tx(port); - return IRQ_HANDLED; - } + + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) + goto disable_tx_irq; count = port->fifosize >> 1; do { @@ -171,8 +170,11 @@ static irqreturn_t clps711xuart_int_tx(i if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); - if (uart_circ_empty(xmit)) - clps711xuart_stop_tx(port); + if (uart_circ_empty(xmit)) { + disable_tx_irq: + disable_irq_nosync(TX_IRQ(port)); + tx_enabled(port) = 0; + } return IRQ_HANDLED; }