From: Zhiyong Tao <zhiyong.tao@mediatek.com>
To: <timur@kernel.org>, <linux@armlinux.org.uk>,
<alcooperx@gmail.com>, <tklauser@distanz.ch>,
<sean.wang@kernel.org>
Cc: <srv_heupstream@mediatek.com>, <zhiyong.tao@mediatek.com>,
<hui.liu@mediatek.com>, <yuchen.huang@mediatek.com>,
<huihui.wang@mediatek.com>, <eddie.huang@mediatek.com>,
<sean.wang@mediatek.com>, <devicetree@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>,
<linux-serial@vger.kernel.org>
Subject: [PATCH] uart: mediatek: fix memory corruption issue
Date: Sat, 10 Jul 2021 17:01:03 +0800 [thread overview]
Message-ID: <20210710090103.2643-2-zhiyong.tao@mediatek.com> (raw)
In-Reply-To: <20210710090103.2643-1-zhiyong.tao@mediatek.com>
This patch is used to fix memory corruption issue when rx power off.
1. add spin lock in mtk8250_dma_rx_complete function in APDMA mode.
2. add processing mechanism which count value is 0
Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
---
drivers/tty/serial/8250/8250_mtk.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index f7d3023f860f..09f7d2166315 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -91,12 +91,15 @@ static void mtk8250_dma_rx_complete(void *param)
struct mtk8250_data *data = up->port.private_data;
struct tty_port *tty_port = &up->port.state->port;
struct dma_tx_state state;
- int copied, total, cnt;
+ unsigned int copied, total, cnt;
unsigned char *ptr;
+ unsigned long flags;
if (data->rx_status == DMA_RX_SHUTDOWN)
return;
+ spin_lock_irqsave(&up->port.lock, flags);
+
dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
total = dma->rx_size - state.residue;
cnt = total;
@@ -104,9 +107,11 @@ static void mtk8250_dma_rx_complete(void *param)
if ((data->rx_pos + cnt) > dma->rx_size)
cnt = dma->rx_size - data->rx_pos;
- ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
- copied = tty_insert_flip_string(tty_port, ptr, cnt);
- data->rx_pos += cnt;
+ if (cnt != 0) {
+ ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+ copied = tty_insert_flip_string(tty_port, ptr, cnt);
+ data->rx_pos += cnt;
+ }
if (total > cnt) {
ptr = (unsigned char *)(dma->rx_buf);
@@ -120,6 +125,8 @@ static void mtk8250_dma_rx_complete(void *param)
tty_flip_buffer_push(tty_port);
mtk8250_rx_dma(up);
+
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static void mtk8250_rx_dma(struct uart_8250_port *up)
--
2.18.0
next prev parent reply other threads:[~2021-07-10 9:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-10 9:01 [PATCH 0/1] Mediatek uart patch Zhiyong Tao
2021-07-10 9:01 ` Zhiyong Tao [this message]
2021-07-21 10:46 ` [PATCH] uart: mediatek: fix memory corruption issue Greg KH
2021-07-22 10:03 ` zhiyong tao
2021-07-22 10:12 ` Greg KH
2021-07-22 11:52 ` zhiyong tao
[not found] ` <CAHp75VeZL53VN0w3O160vMurmRT9ZJzJek6=4X6osqjJDuxD3g@mail.gmail.com>
2021-07-22 9:04 ` zhiyong tao
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