On Fri, Jun 14, 2024 at 04:52:42AM -0700, Breno Leitao wrote:
> Embedding net_device into structures prohibits the usage of flexible
> arrays in the net_device structure. For more details, see the discussion
> at [1].
>
> Un-embed the net_devices from struct mt76_dev by converting them
> into pointers, and allocating them dynamically. Use the leverage
> alloc_netdev_dummy() to allocate the net_device object at
> mt76_dma_init().
>
> The free of the device occurs at mt76_dma_cleanup().
>
> Link: https://lore.kernel.org/all/[email protected]/ [1]
> Signed-off-by: Breno Leitao <[email protected]>
> ---
>
> PS: Due to the lack of hardware, this patch was not tested on a real
> hardware, unfortunately.
>
> PS2: this is the last driver that is still using embedded netdevices.
...
> diff --git a/drivers/net/wireless/mediatek/mt76/dma.h b/drivers/net/wireless/mediatek/mt76/dma.h
> index 1de5a2b20f74..6454a5eca13e 100644
> --- a/drivers/net/wireless/mediatek/mt76/dma.h
> +++ b/drivers/net/wireless/mediatek/mt76/dma.h
> @@ -116,4 +116,9 @@ mt76_dma_should_drop_buf(bool *drop, u32 ctrl, u32 buf1, u32 info)
> }
> }
>
> +static inline struct mt76_dev *mt76_from_netdev(struct net_device *dev)
> +{
> + return *(struct mt76_dev **)netdev_priv(dev);
> +}
> +
> #endif
Hi Breno,
I agree that the above is correct, but I wonder if somehow it
is nicer to avoid explicit casts and instead take advantage of
implicit casting too and from void *.
Maybe something like this:
static inline struct mt76_dev *mt76_from_netdev(struct net_device *dev)
{
struct mt76_dev **priv;
priv = netdev_priv(dev);
return *priv;
}
Further, some of the callers of mt76_from_netdev() cast the return value to
(struct mt7615_dev *). Which seems a bit awkward seeing as it was very
recently a void * (i.e. netdev_priv() returns void *).
I wonder if something like this makes sense, which I believe would avoid
the need for any callers to cast.
static inline void *mt76_priv(struct net_device *dev)
{
struct mt76_dev **priv;
priv = netdev_priv(dev);
return *priv;
}
Ideas above compile tested only.
Other than the above, which is clearly more about style than substance,
this patch looks good to me.
Reviewed-by: Simon Horman <[email protected]>