* [PATCH net-next] net: rmnet: set NETIF_F_LLTX flag
@ 2020-03-08 13:47 Taehee Yoo
2020-03-09 0:28 ` subashab
2020-03-09 4:39 ` David Miller
0 siblings, 2 replies; 4+ messages in thread
From: Taehee Yoo @ 2020-03-08 13:47 UTC (permalink / raw)
To: davem, kuba, subashab, stranche, netdev; +Cc: ap420073
The rmnet_vnd_setup(), which is the callback of ->ndo_start_xmit() is
allowed to call concurrently because it uses RCU protected data.
So, it doesn't need tx lock.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---
drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
index d7c52e398e4a..d58b51d277f1 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
@@ -212,6 +212,8 @@ void rmnet_vnd_setup(struct net_device *rmnet_dev)
rmnet_dev->needs_free_netdev = true;
rmnet_dev->ethtool_ops = &rmnet_ethtool_ops;
+ rmnet_dev->features |= NETIF_F_LLTX;
+
/* This perm addr will be used as interface identifier by IPv6 */
rmnet_dev->addr_assign_type = NET_ADDR_RANDOM;
eth_random_addr(rmnet_dev->perm_addr);
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] net: rmnet: set NETIF_F_LLTX flag
2020-03-08 13:47 [PATCH net-next] net: rmnet: set NETIF_F_LLTX flag Taehee Yoo
@ 2020-03-09 0:28 ` subashab
2020-03-09 0:54 ` Eric Dumazet
2020-03-09 4:39 ` David Miller
1 sibling, 1 reply; 4+ messages in thread
From: subashab @ 2020-03-09 0:28 UTC (permalink / raw)
To: Taehee Yoo; +Cc: davem, kuba, stranche, netdev
On 2020-03-08 07:47, Taehee Yoo wrote:
> The rmnet_vnd_setup(), which is the callback of ->ndo_start_xmit() is
> allowed to call concurrently because it uses RCU protected data.
> So, it doesn't need tx lock.
>
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>
> ---
> drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
> b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
> index d7c52e398e4a..d58b51d277f1 100644
> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
> @@ -212,6 +212,8 @@ void rmnet_vnd_setup(struct net_device *rmnet_dev)
> rmnet_dev->needs_free_netdev = true;
> rmnet_dev->ethtool_ops = &rmnet_ethtool_ops;
>
> + rmnet_dev->features |= NETIF_F_LLTX;
> +
> /* This perm addr will be used as interface identifier by IPv6 */
> rmnet_dev->addr_assign_type = NET_ADDR_RANDOM;
> eth_random_addr(rmnet_dev->perm_addr);
Hi Taehee
It seems the flag is deprecated per documentation.
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/Documentation/networking/netdevices.txt#n73
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] net: rmnet: set NETIF_F_LLTX flag
2020-03-09 0:28 ` subashab
@ 2020-03-09 0:54 ` Eric Dumazet
0 siblings, 0 replies; 4+ messages in thread
From: Eric Dumazet @ 2020-03-09 0:54 UTC (permalink / raw)
To: subashab, Taehee Yoo; +Cc: davem, kuba, stranche, netdev
On 3/8/20 5:28 PM, subashab@codeaurora.org wrote:
> On 2020-03-08 07:47, Taehee Yoo wrote:
>> The rmnet_vnd_setup(), which is the callback of ->ndo_start_xmit() is
>> allowed to call concurrently because it uses RCU protected data.
>> So, it doesn't need tx lock.
>>
>> Signed-off-by: Taehee Yoo <ap420073@gmail.com>
>> ---
>> drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
>> b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
>> index d7c52e398e4a..d58b51d277f1 100644
>> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
>> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
>> @@ -212,6 +212,8 @@ void rmnet_vnd_setup(struct net_device *rmnet_dev)
>> rmnet_dev->needs_free_netdev = true;
>> rmnet_dev->ethtool_ops = &rmnet_ethtool_ops;
>>
>> + rmnet_dev->features |= NETIF_F_LLTX;
>> +
>> /* This perm addr will be used as interface identifier by IPv6 */
>> rmnet_dev->addr_assign_type = NET_ADDR_RANDOM;
>> eth_random_addr(rmnet_dev->perm_addr);
>
> Hi Taehee
>
> It seems the flag is deprecated per documentation.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/Documentation/networking/netdevices.txt#n73
This does not count for virtual drivers, like macvlan, bonding, tunnels...
If your ndo_start_xmit() calls dev_queue_xmit() after switching skb->dev to another device,
you do not need a lock.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] net: rmnet: set NETIF_F_LLTX flag
2020-03-08 13:47 [PATCH net-next] net: rmnet: set NETIF_F_LLTX flag Taehee Yoo
2020-03-09 0:28 ` subashab
@ 2020-03-09 4:39 ` David Miller
1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2020-03-09 4:39 UTC (permalink / raw)
To: ap420073; +Cc: kuba, subashab, stranche, netdev
From: Taehee Yoo <ap420073@gmail.com>
Date: Sun, 8 Mar 2020 13:47:06 +0000
> The rmnet_vnd_setup(), which is the callback of ->ndo_start_xmit() is
> allowed to call concurrently because it uses RCU protected data.
> So, it doesn't need tx lock.
>
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Applied, thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-03-09 4:39 UTC | newest]
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2020-03-08 13:47 [PATCH net-next] net: rmnet: set NETIF_F_LLTX flag Taehee Yoo
2020-03-09 0:28 ` subashab
2020-03-09 0:54 ` Eric Dumazet
2020-03-09 4:39 ` David Miller
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