Re: [PATCH net-next-2.6 v4 1/1] can: c_can: Added support for Bosch C_CAN controller

On 01/12/2011 10:08 AM, Wolfgang Grandegger wrote:

On 01/12/2011 09:51 AM, Bhupesh SHARMA wrote:

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Hi Marc,

Thanks for your review.
Please see my comments inline:

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-----Original Message-----
From: Marc Kleine-Budde [mailto:mkl@pengutronix.de]
On 01/11/2011 12:49 PM, Bhupesh Sharma wrote:

...

quoted

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+static int c_can_close(struct net_device *dev) {
+   struct c_can_priv *priv = netdev_priv(dev);
+
+   netif_stop_queue(dev);
+   napi_disable(&priv->napi);
+   c_can_stop(dev);
+   free_irq(dev->irq, dev);
+   close_candev(dev);
+
+   return 0;
+}
+
+struct net_device *alloc_c_can_dev(void)

Please model after alloc_sja1000_dev:

struct net_device *alloc_sja1000dev(int sizeof_priv)

The private for the _user_ of alloc_c_can_dev is behind the sja1000
private, so you can get rid of the void *priv member in the struct
c_can_priv. (see below)

Ok.
But Wolfgang also suggested to use the *priv* member inside c_can_priv struct
for board specific details. In my c_can platform driver I use it to
store the *clk* variable. Do I need to change that as well?

Marc is referring to:

http://lxr.linux.no/#linux+v2.6.37/drivers/net/can/sja1000/sja1000.c#L582

But also there "priv->priv" is used to store a pointer to the board
specific details. Looking to the SJA1000 drivers, only *one* uses
"sizeof_priv > 0", but many other attach a separately allocated
structure to "priv->priv". For that reason, I'm fine with your current
implementation.

Okay fine with me.

A nice cleanup might be to introduce something like this:

static inline void * give_me_my_priv_from_sja1000_priv
	(struct sja1000_priv *priv)
{
	return (void *)(priv + 1);
}

Marc

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