Sascha Hauer wrote:

Hi,

Here is the second version of the flexcan driver.

Hi Sascha,

some more points i forgot to mention, sorry ...

+/* Structure of the message buffer */
+struct flexcan_mb {
+	u32	can_dlc;
+	u32	can_id;
+	u32	data[2];
+};

This looks really hackish and does not reflect the structure of a flexcan
message buffer! The data is 'u8' and the name of 'dlc' for the
description/flag register is bad.

+
+static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct can_frame *frame = (struct can_frame *)skb->data;
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;

+	u32 can_id;
+	u32 dlc = MB_CNT_CODE(0xc) | (frame->can_dlc << 16);

Naming this variable 'dlc' does not hit the point. See below.

+	u32 *can_data;

Really this needs to be fixed up by defining a proper mailbox struct.

+
+	netif_stop_queue(dev);
+
+	if (frame->can_id & CAN_EFF_FLAG) {
+		can_id = frame->can_id & MB_ID_EXT;

Please use CAN_EFF_MASK here.

+		dlc |= MB_CNT_IDE | MB_CNT_SRR;
+	} else {
+		can_id = (frame->can_id & CAN_SFF_MASK) << 18;
+	}

Just nitpicking for Kernel coding style:
remove the last '{' and '}' pair.

+
+	if (frame->can_id & CAN_RTR_FLAG)
+		dlc |= MB_CNT_RTR;
+
+	writel(dlc, &regs->cantxfg[TX_BUF_ID].can_dlc);
+	writel(can_id, &regs->cantxfg[TX_BUF_ID].can_id);
+
+	can_data = (u32 *)frame->data;
+	writel(cpu_to_be32(*can_data), &regs->cantxfg[TX_BUF_ID].data[0]);
+	writel(cpu_to_be32(*(can_data + 1)), &regs->cantxfg[TX_BUF_ID].data[1]);

IMHO it is not really transparent, that this is a correct handling to copy the
  can_frame.data[] on all architectures. I bet creating a for-statement
regarding the dlc is not slower and makes really clear, what's going on here.

+
+	writel(dlc, &regs->cantxfg[TX_BUF_ID].can_dlc);
+
+	kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
+static void flexcan_rx_frame(struct net_device *ndev,
+		struct flexcan_mb __iomem *mb)
+{
+	struct net_device_stats *stats = &ndev->stats;
+	struct sk_buff *skb;
+	struct can_frame *frame;
+	int ctrl = readl(&mb->can_dlc);

'ctrl' is much better than 'dlc' naming above :-)

+	int length = (ctrl >> 16) & 0x0f;

is probably not enough ... use %9 or an additional check.

+	u32 id;
+
+	skb = dev_alloc_skb(sizeof(struct can_frame));
+	if (!skb) {
+		stats->rx_dropped++;
+		return;
+	}
+
+	frame = (struct can_frame *)skb_put(skb,
+			sizeof(struct can_frame));
+
+	frame->can_dlc = length;
+	id = readl(&mb->can_id) & MB_ID_EXT;

like above use CAN_EFF_MASK

or at least rename MB_ID_EXT to MB_ID_EXT_MASK

+
+	if (ctrl & MB_CNT_IDE) {
+		frame->can_id = id & CAN_EFF_MASK;
+		frame->can_id |= CAN_EFF_FLAG;
+		if (ctrl & MB_CNT_RTR)
+			frame->can_id |= CAN_RTR_FLAG;
+	} else {
+		frame->can_id  = id >> 18;
+		if (ctrl & MB_CNT_RTR)
+			frame->can_id |= CAN_RTR_FLAG;
+	}
+
+	*(u32 *)frame->data = be32_to_cpu(readl(&mb->data[0]));
+	*((u32 *)frame->data + 1) = be32_to_cpu(readl(&mb->data[1]));

Same as above.

Please write readable an maintainable code and let the compiler do his job.

Thanks,
Oliver