[ 07/62] ARM: clps711x: serial driver hungs are a result of call disable_irq within ISR
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-04-24 22:34:21
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3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Shiyan <redacted> 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 <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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; }