linux-kernel - [PATCH 7/7] serial: imx: Fix imx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170630120446.13994-8-romain.perier@collabora.com>
Date:   Fri, 30 Jun 2017 14:04:46 +0200
From:   Romain Perier <romain.perier@...labora.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-serial@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Nandor Han <nandor.han@...com>,
        Romain Perier <romain.perier@...labora.com>
Subject: [PATCH 7/7] serial: imx: Fix imx_shutdown procedure

From: Nandor Han <nandor.han@...com>

In some cases, It looks that interrupts can happen after the dma was
disabled and port was not yet shutdown. This will result in interrupts
handled by imx_rxint.

This commits updates the shutdown function to ensure that underlying
components are disabled in the right order. This disables RX and TX
blocks, then it disabled interrupts. In case DMA is enabled, it disables
DMA and free corresponding resources. It disables UART port and stop
clocks.

Signed-off-by: Nandor Han <nandor.han@...com>
Signed-off-by: Romain Perier <romain.perier@...labora.com>
---
 drivers/tty/serial/imx.c | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index d5b6e09..7dc6f0c 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1404,44 +1404,44 @@ static void imx_shutdown(struct uart_port *port)
 	unsigned long temp;
 	unsigned long flags;
 
-	if (sport->dma_is_enabled) {
-		sport->dma_is_rxing = 0;
-		sport->dma_is_txing = 0;
-		dmaengine_terminate_sync(sport->dma_chan_tx);
-		dmaengine_terminate_sync(sport->dma_chan_rx);
-
+	if (!sport->port.suspended) {
 		spin_lock_irqsave(&sport->port.lock, flags);
 		imx_stop_tx(port);
 		imx_stop_rx(port);
-		imx_disable_dma(sport);
 		spin_unlock_irqrestore(&sport->port.lock, flags);
-		imx_uart_dma_exit(sport);
 	}
 
-	mctrl_gpio_disable_ms(sport->gpios);
+	if (sport->dma_is_inited) {
+		if (sport->dma_is_enabled) {
+			spin_lock_irqsave(&sport->port.lock, flags);
+			imx_disable_dma(sport);
+			spin_unlock_irqrestore(&sport->port.lock, flags);
+		}
+		imx_uart_dma_exit(sport);
+	}
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 	temp = readl(sport->port.membase + UCR2);
-	temp &= ~(UCR2_TXEN);
+	temp &= ~(UCR2_TXEN | UCR2_RXEN);
 	writel(temp, sport->port.membase + UCR2);
+	temp = readl(sport->port.membase + UCR4);
+	temp &= ~UCR4_OREN;
+	writel(temp, sport->port.membase + UCR4);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 
-	/*
-	 * Stop our timer.
-	 */
-	del_timer_sync(&sport->timer);
+	mctrl_gpio_disable_ms(sport->gpios);
 
-	/*
-	 * Disable all interrupts, port and break condition.
-	 */
+	/* Stop our timer. */
+	del_timer_sync(&sport->timer);
 
+	/* Disable port. */
 	spin_lock_irqsave(&sport->port.lock, flags);
 	temp = readl(sport->port.membase + UCR1);
-	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
-
+	temp &= ~UCR1_UARTEN;
 	writel(temp, sport->port.membase + UCR1);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 
+	/* Disable clocks. */
 	clk_disable_unprepare(sport->clk_per);
 	clk_disable_unprepare(sport->clk_ipg);
 }
-- 
1.8.3.1