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Message-ID: <20121123134027.GA32098@hposo>
Date: Fri, 23 Nov 2012 14:40:27 +0100
From: Olivier Sobrie <olivier@...rie.be>
To: Marc Kleine-Budde <mkl@...gutronix.de>, linux-can@...r.kernel.org
Cc: Greg KH <gregkh@...uxfoundation.org>,
Wolfgang Grandegge <wg@...ndegger.com>, netdev@...r.kernel.org,
linux-usb@...r.kernel.org, Daniel Berglund <db@...ser.com>
Subject: Re: [PATCH] kvaser_usb: fix "dma on the stack" errors
On Fri, Nov 23, 2012 at 02:30:28PM +0100, Olivier Sobrie wrote:
> The dma buffer given to usb_bulk_msg() must be allocated and not on
> the stack.
> See Documentation/DMA-API-HOWTO.txt section "What memory is DMA'able?"
>
> Signed-off-by: Olivier Sobrie <olivier@...rie.be>
> ---
> Here is the incremental patch.
> Thank you Greg !
>
> Olivier
>
> drivers/net/can/usb/kvaser_usb.c | 110 ++++++++++++++++++++++++--------------
> 1 file changed, 69 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
> index 8807bf8..7ac6e82 100644
> --- a/drivers/net/can/usb/kvaser_usb.c
> +++ b/drivers/net/can/usb/kvaser_usb.c
> @@ -421,14 +421,21 @@ end:
> static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
> u8 msg_id, int channel)
> {
> - struct kvaser_msg msg = {
> - .len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple),
> - .id = msg_id,
> - .u.simple.channel = channel,
> - .u.simple.tid = 0xff,
> - };
> -
> - return kvaser_usb_send_msg(dev, &msg);
> + struct kvaser_msg *msg;
> + int rc;
> +
> + msg = kmalloc(sizeof(*msg), GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
Doh! I removed by mistake the line "msg->id = msg_id"... grr
> + msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
> + msg->u.simple.channel = channel;
> + msg->u.simple.tid = 0xff;
> +
> + rc = kvaser_usb_send_msg(dev, msg);
> +
> + kfree(msg);
> + return rc;
> }
>
> static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
> @@ -1057,20 +1064,27 @@ static int kvaser_usb_setup_rx_urbs(struct kvaser_usb *dev)
>
> static int kvaser_usb_set_opt_mode(const struct kvaser_usb_net_priv *priv)
> {
> - struct kvaser_msg msg = {
> - .id = CMD_SET_CTRL_MODE,
> - .len = MSG_HEADER_LEN +
> - sizeof(struct kvaser_msg_ctrl_mode),
> - .u.ctrl_mode.tid = 0xff,
> - .u.ctrl_mode.channel = priv->channel,
> - };
> + struct kvaser_msg *msg;
> + int rc;
> +
> + msg = kmalloc(sizeof(*msg), GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->id = CMD_SET_CTRL_MODE;
> + msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_ctrl_mode);
> + msg->u.ctrl_mode.tid = 0xff;
> + msg->u.ctrl_mode.channel = priv->channel;
>
> if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> - msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
> + msg->u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
> else
> - msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
> + msg->u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
> +
> + rc = kvaser_usb_send_msg(priv->dev, msg);
>
> - return kvaser_usb_send_msg(priv->dev, &msg);
> + kfree(msg);
> + return rc;
> }
>
> static int kvaser_usb_start_chip(struct kvaser_usb_net_priv *priv)
> @@ -1163,15 +1177,22 @@ static int kvaser_usb_stop_chip(struct kvaser_usb_net_priv *priv)
>
> static int kvaser_usb_flush_queue(struct kvaser_usb_net_priv *priv)
> {
> - struct kvaser_msg msg = {
> - .id = CMD_FLUSH_QUEUE,
> - .len = MSG_HEADER_LEN +
> - sizeof(struct kvaser_msg_flush_queue),
> - .u.flush_queue.channel = priv->channel,
> - .u.flush_queue.flags = 0x00,
> - };
> -
> - return kvaser_usb_send_msg(priv->dev, &msg);
> + struct kvaser_msg *msg;
> + int rc;
> +
> + msg = kmalloc(sizeof(*msg), GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->id = CMD_FLUSH_QUEUE;
> + msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_flush_queue);
> + msg->u.flush_queue.channel = priv->channel;
> + msg->u.flush_queue.flags = 0x00;
> +
> + rc = kvaser_usb_send_msg(priv->dev, msg);
> +
> + kfree(msg);
> + return rc;
> }
>
> static int kvaser_usb_close(struct net_device *netdev)
> @@ -1364,24 +1385,31 @@ static int kvaser_usb_set_bittiming(struct net_device *netdev)
> struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
> struct can_bittiming *bt = &priv->can.bittiming;
> struct kvaser_usb *dev = priv->dev;
> - struct kvaser_msg msg = {
> - .id = CMD_SET_BUS_PARAMS,
> - .len = MSG_HEADER_LEN +
> - sizeof(struct kvaser_msg_busparams),
> - .u.busparams.channel = priv->channel,
> - .u.busparams.tid = 0xff,
> - .u.busparams.bitrate = cpu_to_le32(bt->bitrate),
> - .u.busparams.sjw = bt->sjw,
> - .u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1,
> - .u.busparams.tseg2 = bt->phase_seg2,
> - };
> + struct kvaser_msg *msg;
> + int rc;
> +
> + msg = kmalloc(sizeof(*msg), GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->id = CMD_SET_BUS_PARAMS;
> + msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_busparams);
> + msg->u.busparams.channel = priv->channel;
> + msg->u.busparams.tid = 0xff;
> + msg->u.busparams.bitrate = cpu_to_le32(bt->bitrate);
> + msg->u.busparams.sjw = bt->sjw;
> + msg->u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1;
> + msg->u.busparams.tseg2 = bt->phase_seg2;
>
> if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
> - msg.u.busparams.no_samp = 3;
> + msg->u.busparams.no_samp = 3;
> else
> - msg.u.busparams.no_samp = 1;
> + msg->u.busparams.no_samp = 1;
> +
> + rc = kvaser_usb_send_msg(dev, msg);
>
> - return kvaser_usb_send_msg(dev, &msg);
> + kfree(msg);
> + return rc;
> }
>
> static int kvaser_usb_set_mode(struct net_device *netdev,
> --
> 1.7.9.5
>
--
Olivier
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