[PATCH v3 0/2] usb: gadget: u_ether: revert netif_device_detach change

[PATCH v3 0/2] usb: gadget: u_ether: revert netif_device_detach change

[Ferry Toth]

As agreed with the author, the netif_device_detach change is going to be reverted by
this series, so we will collaborate on a new one in the future that
brings no regressions.

v3:
- Send out actual version (Ferry)

v2:
- Add SoB (Greg)

Ferry Toth (2):
  Revert "usb: gadget: u_ether: Re-attach netif device to mirror
    detachment"
  Revert "usb: gadget: u_ether: Replace netif_stop_queue with
    netif_device_detach"

 drivers/usb/gadget/function/u_ether.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

-- 
2.43.0

[PATCH v3 1/2] Revert "usb: gadget: u_ether: Re-attach netif device to mirror detachment"

[Ferry Toth]

This reverts commit 76c945730cdffb572c7767073cc6515fd3f646b4.

Prerequisite revert for the reverting of the original commit f49449fbc21e.

Fixes: 76c945730cdf ("usb: gadget: u_ether: Re-attach netif device to mirror detachment")
Fixes: f49449fbc21e ("usb: gadget: u_ether: Replace netif_stop_queue with netif_device_detach")
Reported-by: Ferry Toth <fntoth@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ferry Toth <fntoth@gmail.com>
---
 drivers/usb/gadget/function/u_ether.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
index 11dd0b9e847f..aa0511c3a62c 100644
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -1163,8 +1163,6 @@ struct net_device *gether_connect(struct gether *link)
 		if (netif_running(dev->net))
 			eth_start(dev, GFP_ATOMIC);
 
-		netif_device_attach(dev->net);
-
 	/* on error, disable any endpoints  */
 	} else {
 		(void) usb_ep_disable(link->out_ep);
-- 
2.43.0

[PATCH v3 2/2] Revert "usb: gadget: u_ether: Replace netif_stop_queue with netif_device_detach"

[Ferry Toth]

This reverts commit f49449fbc21e7e9550a5203902d69c8ae7dfd918.

This commit breaks u_ether on some setups (at least Merrifield). The fix
"usb: gadget: u_ether: Re-attach netif device to mirror detachment" party
restores u-ether. However the netif usb: remains up even usb is switched
from device to host mode. This creates problems for user space as the
interface remains in the routing table while not realy present and network
managers (connman) not detecting a network change.

Various attempts to find the root cause were unsuccesful up to now. Therefore
revert until a solution is found.

Link: https://lore.kernel.org/linux-usb/20231006141231.7220-1-hgajjar@de.adit-jv.com/
Reported-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reported-by: Ferry Toth <fntoth@gmail.com>
Fixes: f49449fbc21e ("usb: gadget: u_ether: Replace netif_stop_queue with netif_device_detach")
Cc: stable@vger.kernel.org
Signed-off-by: Ferry Toth <fntoth@gmail.com>
---
 drivers/usb/gadget/function/u_ether.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
index aa0511c3a62c..95191083b455 100644
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -1200,7 +1200,7 @@ void gether_disconnect(struct gether *link)
 
 	DBG(dev, "%s\n", __func__);
 
-	netif_device_detach(dev->net);
+	netif_stop_queue(dev->net);
 	netif_carrier_off(dev->net);
 
 	/* disable endpoints, forcing (synchronous) completion
-- 
2.43.0

Re: [PATCH v3 0/2] usb: gadget: u_ether: revert netif_device_detach change

[Greg Kroah-Hartman]

On Thu, Jun 20, 2024 at 10:46:40PM +0200, Ferry Toth wrote:
> As agreed with the author, the netif_device_detach change is going to be reverted by
> this series, so we will collaborate on a new one in the future that
> brings no regressions.
> 
> v3:
> - Send out actual version (Ferry)

Much better, thanks, now queued up!

greg k-h