From: Breno Leitao <leitao@debian.org>
To: Kalle Valo <kvalo@kernel.org>
Cc: kuba@kernel.org, ath11k@lists.infradead.org,
ath10k@lists.infradead.org, linux-wireless@vger.kernel.org,
imitsyanko@quantenna.com, geomatsi@gmail.com,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 0/3] wifi: Un-embed ath10k and ath11k dummy netdev
Date: Mon, 8 Apr 2024 12:33:55 -0700 [thread overview]
Message-ID: <ZhRGo3I57rXxsMV/@gmail.com> (raw)
In-Reply-To: <87pluz24ap.fsf@kernel.org>
On Mon, Apr 08, 2024 at 07:43:42PM +0300, Kalle Valo wrote:
> Breno Leitao <leitao@debian.org> writes:
> > On Fri, Apr 05, 2024 at 06:15:05PM +0300, Kalle Valo wrote:
> >> Breno Leitao <leitao@debian.org> writes:
> >>
> >> > struct net_device shouldn't be embedded into any structure, instead,
> >> > the owner should use the private space to embed their state into
> >> > net_device.
> >> >
> >> > This patch set fixes the problem above for ath10k and ath11k. This also
> >> > fixes the conversion of qtnfmac driver to the new helper.
> >> >
> >> > This patch set depends on a series that is still under review:
> >> > https://lore.kernel.org/all/20240404114854.2498663-1-leitao@debian.org/#t
> >> >
> >> > If it helps, I've pushed the tree to
> >> > https://github.com/leitao/linux/tree/wireless-dummy
> >> >
> >> > PS: Due to lack of hardware, unfortunately all these patches are
> >> > compiled tested only.
> >> >
> >> > Breno Leitao (3):
> >> > wifi: qtnfmac: Use netdev dummy allocator helper
> >> > wifi: ath10k: allocate dummy net_device dynamically
> >> > wifi: ath11k: allocate dummy net_device dynamically
> >>
> >> Thanks for setting up the branch, that makes the testing very easy. I
> >> now tested the branch using the commit below with ath11k WCN6855 hw2.0
> >> on an x86 box:
> >>
> >> 5be9a125d8e7 wifi: ath11k: allocate dummy net_device dynamically
> >>
> >> But unfortunately it crashes, the stack trace below. I can easily test
> >> your branches, just let me know what to test. A direct 'git pull'
> >> command is the best.
> >
> > Thanks for the test.
> >
> > Reading the issue, I am afraid that freeing netdev explicitly
> > (free_netdev()) might not be the best approach at the exit path.
> >
> > I would like to try to leverage the ->needs_free_netdev netdev
> > mechanism to do the clean-up, if that makes sense. I've updated the
> > ath11k patch, and I am curious if that is what we want.
> >
> > Would you mind testing a net patch I have, please?
> >
> > https://github.com/leitao/linux/tree/wireless-dummy_v2
>
> I tested this again with my WCN6855 hw2.0 x86 test box on this commit:
>
> a87674ac820e wifi: ath11k: allocate dummy net_device dynamically
>
> It passes my tests and doesn't crash, but I see this kmemleak warning a
> lot:
Thanks Kalle, that was helpful. The device is not being clean-up
automatically.
Chatting with Jakub, he suggested coming back to the original approach,
but, adding a additional patch, at the free_netdev().
Would you mind running another test, please?
https://github.com/leitao/linux/tree/wireless-dummy_v3
The branch above is basically the original branch (as in this patch
series), with this additional patch:
Author: Breno Leitao <leitao@debian.org>
Date: Mon Apr 8 11:37:32 2024 -0700
net: free_netdev: exit earlier if dummy
For dummy devices, exit earlier at free_netdev() instead of executing
the whole function. This is necessary, because dummy devices are
special, and shouldn't have the second part of the function executed.
Otherwise reg_state, which is NETREG_DUMMY, will be overwritten and
there will be no way to identify that this is a dummy device. Also, this
device do not need the final put_device(), since dummy devices are not
registered (through register_netdevice()), where the device reference is
increased (at netdev_register_kobject()/device_add()).
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
diff --git a/net/core/dev.c b/net/core/dev.c
index 2b82bd1cd2f8..5d2cb97d0ae6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11058,7 +11058,8 @@ void free_netdev(struct net_device *dev)
dev->xdp_bulkq = NULL;
/* Compatibility with error handling in drivers */
- if (dev->reg_state == NETREG_UNINITIALIZED) {
+ if (dev->reg_state == NETREG_UNINITIALIZED ||
+ dev->reg_state == NETREG_DUMMY) {
netdev_freemem(dev);
return;
}
next prev parent reply other threads:[~2024-04-08 19:34 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-05 12:21 [PATCH 0/3] wifi: Un-embed ath10k and ath11k dummy netdev Breno Leitao
2024-04-05 12:21 ` [PATCH 1/3] wifi: qtnfmac: Use netdev dummy allocator helper Breno Leitao
2024-04-05 12:21 ` [PATCH 2/3] wifi: ath10k: allocate dummy net_device dynamically Breno Leitao
2024-04-05 12:21 ` [PATCH 3/3] wifi: ath11k: " Breno Leitao
2024-04-05 15:15 ` [PATCH 0/3] wifi: Un-embed ath10k and ath11k dummy netdev Kalle Valo
2024-04-08 13:33 ` Breno Leitao
2024-04-08 16:43 ` Kalle Valo
2024-04-08 19:33 ` Breno Leitao [this message]
2024-04-09 10:03 ` Kalle Valo
2024-04-09 10:51 ` Breno Leitao
2024-04-09 11:40 ` Kalle Valo
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