2024-05-03 10:33:19

by Breno Leitao

Subject: [PATCH wireless-next] wil6210: Do not use embedded netdev in wil6210_priv

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_device from struct wil6210_priv by converting it
into a pointer. Then use the leverage alloc_netdev_dummy() to allocate
the net_device object at wil_if_add(). The free of the device
occurs at wil_if_remove().

[1] https://lore.kernel.org/all/[email protected]/

Signed-off-by: Breno Leitao <[email protected]>
---
drivers/net/wireless/ath/wil6210/netdev.c | 21 +++++++++++++++------
drivers/net/wireless/ath/wil6210/wil6210.h | 2 +-
2 files changed, 16 insertions(+), 7 deletions(-)

PS: I only compile-tested this patch due to lack of hardware.

diff --git a/drivers/net/wireless/ath/wil6210/netdev.c b/drivers/net/wireless/ath/wil6210/netdev.c
index ee7d7e9c2718..d5d364683c0e 100644
--- a/drivers/net/wireless/ath/wil6210/netdev.c
+++ b/drivers/net/wireless/ath/wil6210/netdev.c
@@ -453,16 +453,21 @@ int wil_if_add(struct wil6210_priv *wil)
return rc;
}

- init_dummy_netdev(&wil->napi_ndev);
+ wil->napi_ndev = alloc_netdev_dummy(0);
+ if (!wil->napi_ndev) {
+ wil_err(wil, "failed to allocate dummy netdev");
+ rc = -ENOMEM;
+ goto out_wiphy;
+ }
if (wil->use_enhanced_dma_hw) {
- netif_napi_add(&wil->napi_ndev, &wil->napi_rx,
+ netif_napi_add(wil->napi_ndev, &wil->napi_rx,
wil6210_netdev_poll_rx_edma);
- netif_napi_add_tx(&wil->napi_ndev,
+ netif_napi_add_tx(wil->napi_ndev,
&wil->napi_tx, wil6210_netdev_poll_tx_edma);
} else {
- netif_napi_add(&wil->napi_ndev, &wil->napi_rx,
+ netif_napi_add(wil->napi_ndev, &wil->napi_rx,
wil6210_netdev_poll_rx);
- netif_napi_add_tx(&wil->napi_ndev,
+ netif_napi_add_tx(wil->napi_ndev,
&wil->napi_tx, wil6210_netdev_poll_tx);
}

@@ -474,10 +479,12 @@ int wil_if_add(struct wil6210_priv *wil)
wiphy_unlock(wiphy);
rtnl_unlock();
if (rc < 0)
- goto out_wiphy;
+ goto free_dummy;

return 0;

+free_dummy:
+ free_netdev(wil->napi_ndev);
out_wiphy:
wiphy_unregister(wiphy);
return rc;
@@ -554,5 +561,7 @@ void wil_if_remove(struct wil6210_priv *wil)
netif_napi_del(&wil->napi_tx);
netif_napi_del(&wil->napi_rx);

+ free_netdev(wil->napi_ndev);
+
wiphy_unregister(wiphy);
}
diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h
index 22a6eb3e12b7..9bd1286d2857 100644
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -983,7 +983,7 @@ struct wil6210_priv {
spinlock_t eap_lock; /* guarding access to eap rekey fields */
struct napi_struct napi_rx;
struct napi_struct napi_tx;
- struct net_device napi_ndev; /* dummy net_device serving all VIFs */
+ struct net_device *napi_ndev; /* dummy net_device serving all VIFs */

/* DMA related */
struct wil_ring ring_rx;
--
2.43.0

2024-05-04 14:48:16

by Simon Horman

Subject: Re: [PATCH wireless-next] wil6210: Do not use embedded netdev in wil6210_priv

On Fri, May 03, 2024 at 03:32:56AM -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_device from struct wil6210_priv by converting it
> into a pointer. Then use the leverage alloc_netdev_dummy() to allocate
> the net_device object at wil_if_add(). The free of the device
> occurs at wil_if_remove().
>
> [1] https://lore.kernel.org/all/[email protected]/
>
> Signed-off-by: Breno Leitao <[email protected]>

Reviewed-by: Simon Horman <[email protected]>

2024-05-07 10:05:43

by Kalle Valo

Subject: Re: [PATCH wireless-next] wil6210: Do not use embedded netdev in wil6210_priv

Breno Leitao <[email protected]> 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_device from struct wil6210_priv by converting it
> into a pointer. Then use the leverage alloc_netdev_dummy() to allocate
> the net_device object at wil_if_add(). The free of the device
> occurs at wil_if_remove().
>
> Link: https://lore.kernel.org/all/[email protected]/ [1]
> Signed-off-by: Breno Leitao <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>

Patch applied to ath-next branch of ath.git, thanks.

10d2b4f4aa0b wifi: wil6210: Do not use embedded netdev in wil6210_priv

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches