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authorLoic Poulain <loic.poulain@intel.com>2014-04-24 11:38:56 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-04-25 00:18:02 +0200
commitb08c9c317e3f7764a91d522cd031639ba42b98cc (patch)
tree7d0f1387ed4c14229923b1c8b8239032dcc00173 /drivers
parenttty: Fix race condition between __tty_buffer_request_room and flush_to_ldisc (diff)
downloadlinux-b08c9c317e3f7764a91d522cd031639ba42b98cc.tar.xz
linux-b08c9c317e3f7764a91d522cd031639ba42b98cc.zip
8250_core: Fix unwanted TX chars write
On transmit-hold-register empty, serial8250_tx_chars should be called only if we don't use DMA. DMA has its own tx cycle. Signed-off-by: Loic Poulain <loic.poulain@intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/tty/serial/8250/8250_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 81f909c2101f..0e1bf8858431 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1520,7 +1520,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
status = serial8250_rx_chars(up, status);
}
serial8250_modem_status(up);
- if (status & UART_LSR_THRE)
+ if (!up->dma && (status & UART_LSR_THRE))
serial8250_tx_chars(up);
spin_unlock_irqrestore(&port->lock, flags);