Commit 3d3c817c authored by Srinivas Neeli's avatar Srinivas Neeli Committed by Marc Kleine-Budde
Browse files

can: xilinx_can: Fix usage of skb memory 

As per linux can framework, driver not allowed to touch the skb memory
after can_put_echo_skb() call.
This patch fixes the same.
https://www.spinics.net/lists/linux-can/msg02199.html



Signed-off-by: default avatarSrinivas Neeli <srinivas.neeli@xilinx.com>
Reviewed-by: default avatarAppana Durga Kedareswara Rao <appana.durga.rao@xilinx.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent b848238d

drivers/net/can/xilinx_can.c

+13 −12
Original line number Diff line number Diff line
@@ -542,16 +542,17 @@ static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode) 


/**

 * xcan_write_frame - Write a frame to HW

 * @priv:		Driver private data structure

 * @ndev:		Pointer to net_device structure

 * @skb:		sk_buff pointer that contains data to be Txed

 * @frame_offset:	Register offset to write the frame to

 */

static void xcan_write_frame(struct xcan_priv *priv, struct sk_buff *skb,

static void xcan_write_frame(struct net_device *ndev, struct sk_buff *skb,

			     int frame_offset)

{

	u32 id, dlc, data[2] = {0, 0};

	struct canfd_frame *cf = (struct canfd_frame *)skb->data;

	u32 ramoff, dwindex = 0, i;

	struct xcan_priv *priv = netdev_priv(ndev);



	/* Watch carefully on the bit sequence */

	if (cf->can_id & CAN_EFF_FLAG) {
@@ -587,6 +588,14 @@ static void xcan_write_frame(struct xcan_priv *priv, struct sk_buff *skb, 
		dlc |= XCAN_DLCR_EDL_MASK;

	}



	if (!(priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES) &&

	    (priv->devtype.flags & XCAN_FLAG_TXFEMP))

		can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);

	else

		can_put_echo_skb(skb, ndev, 0);



	priv->tx_head++;



	priv->write_reg(priv, XCAN_FRAME_ID_OFFSET(frame_offset), id);

	/* If the CAN frame is RTR frame this write triggers transmission

	 * (not on CAN FD)
@@ -638,13 +647,9 @@ static int xcan_start_xmit_fifo(struct sk_buff *skb, struct net_device *ndev) 
			XCAN_SR_TXFLL_MASK))

		return -ENOSPC;



	can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);



	spin_lock_irqsave(&priv->tx_lock, flags);



	priv->tx_head++;



	xcan_write_frame(priv, skb, XCAN_TXFIFO_OFFSET);

	xcan_write_frame(ndev, skb, XCAN_TXFIFO_OFFSET);



	/* Clear TX-FIFO-empty interrupt for xcan_tx_interrupt() */

	if (priv->tx_max > 1)
@@ -675,13 +680,9 @@ static int xcan_start_xmit_mailbox(struct sk_buff *skb, struct net_device *ndev) 
		     BIT(XCAN_TX_MAILBOX_IDX)))

		return -ENOSPC;



	can_put_echo_skb(skb, ndev, 0);



	spin_lock_irqsave(&priv->tx_lock, flags);



	priv->tx_head++;



	xcan_write_frame(priv, skb,

	xcan_write_frame(ndev, skb,

			 XCAN_TXMSG_FRAME_OFFSET(XCAN_TX_MAILBOX_IDX));



	/* Mark buffer as ready for transmit */

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