On 04/01/24 22:49, Simon Horman wrote:
> On Tue, Jan 02, 2024 at 03:59:49PM +0530, Bhavya Kapoor wrote:
>> When multiple CAN's are present, then names that are getting assigned
>> changes after every boot even after providing alias in the device tree.
>> Thus, Add support for implementing CAN aliasing so that names or
>> alias for CAN will now be provided from device tree.
>>
>> Signed-off-by: Bhavya Kapoor <b-kapoor@xxxxxx>
> Hi Bhavya,
>
> some minor feedback from my side.
>
> ...
>
>> diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
>> index 3a3be5cdfc1f..ed483c23ec79 100644
>> --- a/drivers/net/can/dev/dev.c
>> +++ b/drivers/net/can/dev/dev.c
>> @@ -247,12 +247,14 @@ void can_setup(struct net_device *dev)
>>
>> /* Allocate and setup space for the CAN network device */
>> struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
>> - unsigned int txqs, unsigned int rxqs)
>> + unsigned int txqs, unsigned int rxqs,
>> + struct device *candev)
>> {
>> struct can_ml_priv *can_ml;
>> struct net_device *dev;
>> struct can_priv *priv;
>> - int size;
>> + int size, aliasid;
>> + char devname[6] = "can%d";
> nit: Please consider arranging local variables in Networking code
> in reverse xmas tree order - longest line to shortest.
Okay, i will keep this in mind from next time.
>
>>
>> /* We put the driver's priv, the CAN mid layer priv and the
>> * echo skb into the netdevice's priv. The memory layout for
>> @@ -273,7 +275,14 @@ struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
>> size = ALIGN(size, sizeof(struct sk_buff *)) +
>> echo_skb_max * sizeof(struct sk_buff *);
>>
>> - dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
>> + if (candev) {
>> + aliasid = of_alias_get_id(candev->of_node, "can");
>> + if (aliasid >= 0)
>> + snprintf(devname, sizeof(devname), "%s%d", "can", aliasid);
> The size of devname is 6 bytes (can%d\0).
> This means that snprintf() will truncate devname if alias is greater than 99.
> Is this a concern?
When sequential naming will be done from can0 in aliases for can,
considering that 99 is still a very large number and so 6 bytes for
devname should suffice.
Regards
> If so, perhaps devname could be declared to be IFNAMSIZ bytes long?
>
> Flagged by gcc-13 -Wformat-truncation
>
>> + }
>> + dev_dbg(candev, "Name of CAN assigned is : %s\n", devname);
>> +
>> + dev = alloc_netdev_mqs(size, devname, NET_NAME_UNKNOWN, can_setup,
>> txqs, rxqs);
>> if (!dev)
>> return NULL;
> ...
