From: Soren Brinkmann <soren.brinkmann@xilinx.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>
Cc: Michal Simek <michal.simek@xilinx.com>,
<linux-serial@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
"Soren Brinkmann" <soren.brinkmann@xilinx.com>
Subject: [PATCH v2 07/10] tty: xuartps: Acquire port lock for shutdown
Date: Wed, 4 Nov 2015 23:21:16 -0800 [thread overview]
Message-ID: <1446708079-1105-8-git-send-email-soren.brinkmann@xilinx.com> (raw)
In-Reply-To: <1446708079-1105-1-git-send-email-soren.brinkmann@xilinx.com>
Shutting down the UART port can happen while console operations are in
progress. Holding the port lock serializes these operations and avoids
the UART HW to be disabled in the middle of console prints.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
---
drivers/tty/serial/xilinx_uartps.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 5efd1b9d220f..7fd226d65496 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -823,6 +823,9 @@ static int cdns_uart_startup(struct uart_port *port)
static void cdns_uart_shutdown(struct uart_port *port)
{
int status;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
/* Disable interrupts */
status = readl(port->membase + CDNS_UART_IMR_OFFSET);
@@ -832,6 +835,9 @@ static void cdns_uart_shutdown(struct uart_port *port)
/* Disable the TX and RX */
writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
port->membase + CDNS_UART_CR_OFFSET);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
free_irq(port->irq, port);
}
--
2.6.2.3.ga463a5b
next prev parent reply other threads:[~2015-11-05 7:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-05 7:21 [PATCH v2 00/10] tty: xuartps: Fix lock ups Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 01/10] tty: xuartps: Beautify read-modify writes Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 02/10] tty: xuartps: Use spinlock to serialize HW access Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 03/10] tty: xuartps: Always enable transmitter in start_tx Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 04/10] tty: xuartps: Clear interrupt status register in shutdown Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 05/10] tty: xuartps: Improve startup function Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 06/10] tty: xuartps: Keep lock for whole ISR Soren Brinkmann
2015-11-05 7:21 ` Soren Brinkmann [this message]
2015-11-05 7:21 ` [PATCH v2 08/10] tty: xuartps: Move RX path into helper function Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 09/10] tty: xuartps: Only handle RX IRQs when RX is enabled Soren Brinkmann
2015-11-05 7:21 ` [PATCH v2 10/10] tty: xuartps: Cleanup: Reformat if-else Soren Brinkmann
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