Hi Greg,
Tony Lindgren <tony@xxxxxxxxxxx> writes:
> Hi,
>
> Looks like commit c9ffc78745f8 ("usb: gadget: NCM: Protect dev->port_usb
> using dev->lock") causes hangs for me with Linux next.
>
> Reverting c9ffc78745f8 makes the issues go away, some more info below.
Can you revert this commit from your tree?
Here's the full commit for reference:
commit c9ffc78745f89e300fe704348dd8e6800acf4d18
Author: Harish Jenny K N <harish_kandiga@xxxxxxxxxx>
Date: Fri Sep 9 11:30:42 2016 +0200
usb: gadget: NCM: Protect dev->port_usb using dev->lock
This commit incorporates findings from
https://lkml.org/lkml/2016/4/25/594
The function has been modified to make sure we hold
the dev lock when accessing the net device pointer.
Acked-by: Jim Baxter <jim_baxter@xxxxxxxxxx>
Signed-off-by: Harish Jenny K N <harish_kandiga@xxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
index 9c8c9ed1dc9e..8cb08033b7c1 100644
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -553,14 +553,16 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
skb = dev->wrap(dev->port_usb, skb);
- spin_unlock_irqrestore(&dev->lock, flags);
if (!skb) {
/* Multi frame CDC protocols may store the frame for
* later which is not a dropped frame.
*/
if (dev->port_usb &&
- dev->port_usb->supports_multi_frame)
+ dev->port_usb->supports_multi_frame) {
+ spin_unlock_irqrestore(&dev->lock, flags);
goto multiframe;
+ }
+ spin_unlock_irqrestore(&dev->lock, flags);
goto drop;
}
}
--
balbi
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