FAILED: patch "[PATCH] USB: gadget: core: adjust uevent timing on gadget unbind" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] USB: gadget: core: adjust uevent timing on gadget unbind" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 73ea73affe8622bdf292de898da869d441da6a9d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023121132-these-deviation-5ab6@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

73ea73affe86 ("USB: gadget: core: adjust uevent timing on gadget unbind")
50966da807c8 ("usb: gadget: udc: core: Offload usb_udc_vbus_handler processing")
1016fc0c096c ("USB: gadget: Fix obscure lockdep violation for udc_mutex")
f9d76d15072c ("USB: gadget: Add ID numbers to gadget names")
fc274c1e9973 ("USB: gadget: Add a new bus for gadgets")
6ebb449f9f25 ("USB: gadget: Register udc before gadget")
af1969a2d734 ("USB: gadget: Rename usb_gadget_probe_driver()")
710f5d627a98 ("Merge tag 'usb-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 73ea73affe8622bdf292de898da869d441da6a9d Mon Sep 17 00:00:00 2001
From: Roy Luo <royluo@google.com>
Date: Tue, 28 Nov 2023 22:17:56 +0000
Subject: [PATCH] USB: gadget: core: adjust uevent timing on gadget unbind

The KOBJ_CHANGE uevent is sent before gadget unbind is actually
executed, resulting in inaccurate uevent emitted at incorrect timing
(the uevent would have USB_UDC_DRIVER variable set while it would
soon be removed).
Move the KOBJ_CHANGE uevent to the end of the unbind function so that
uevent is sent only after the change has been made.

Fixes: 2ccea03a8f7e ("usb: gadget: introduce UDC Class")
Cc: stable@vger.kernel.org
Signed-off-by: Roy Luo <royluo@google.com>
Link: https://lore.kernel.org/r/20231128221756.2591158-1-royluo@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index ded9531f141b..d59f94464b87 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1646,8 +1646,6 @@ static void gadget_unbind_driver(struct device *dev)
 
 	dev_dbg(&udc->dev, "unbinding gadget driver [%s]\n", driver->function);
 
-	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
-
 	udc->allow_connect = false;
 	cancel_work_sync(&udc->vbus_work);
 	mutex_lock(&udc->connect_lock);
@@ -1667,6 +1665,8 @@ static void gadget_unbind_driver(struct device *dev)
 	driver->is_bound = false;
 	udc->driver = NULL;
 	mutex_unlock(&udc_lock);
+
+	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 }
 
 /* ------------------------------------------------------------------------- */

[PATCH 5.10.y] USB: gadget: core: adjust uevent timing on gadget unbind

[Roy Luo]

The KOBJ_CHANGE uevent is sent before gadget unbind is actually
executed, resulting in inaccurate uevent emitted at incorrect timing
(the uevent would have USB_UDC_DRIVER variable set while it would
soon be removed).
Move the KOBJ_CHANGE uevent to the end of the unbind function so that
uevent is sent only after the change has been made.

Fixes: 2ccea03a8f7e ("usb: gadget: introduce UDC Class")
Cc: stable@vger.kernel.org
Signed-off-by: Roy Luo <royluo@google.com>
Link: https://lore.kernel.org/r/20231128221756.2591158-1-royluo@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 73ea73affe8622bdf292de898da869d441da6a9d)
---
 drivers/usb/gadget/udc/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 14d9d1ee16fc..7b3c0787d5a4 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1353,8 +1353,6 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
 	dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
 			udc->driver->function);
 
-	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
-
 	usb_gadget_disconnect(udc->gadget);
 	if (udc->gadget->irq)
 		synchronize_irq(udc->gadget->irq);
@@ -1363,6 +1361,8 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
 
 	udc->driver = NULL;
 	udc->gadget->dev.driver = NULL;
+
+	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 }
 
 /**
-- 
2.43.0.472.g3155946c3a-goog

Re: [PATCH 5.10.y] USB: gadget: core: adjust uevent timing on gadget unbind

[Greg Kroah-Hartman]

On Fri, Dec 15, 2023 at 02:15:07AM +0000, Roy Luo wrote:
> The KOBJ_CHANGE uevent is sent before gadget unbind is actually
> executed, resulting in inaccurate uevent emitted at incorrect timing
> (the uevent would have USB_UDC_DRIVER variable set while it would
> soon be removed).
> Move the KOBJ_CHANGE uevent to the end of the unbind function so that
> uevent is sent only after the change has been made.
> 
> Fixes: 2ccea03a8f7e ("usb: gadget: introduce UDC Class")
> Cc: stable@vger.kernel.org
> Signed-off-by: Roy Luo <royluo@google.com>
> Link: https://lore.kernel.org/r/20231128221756.2591158-1-royluo@google.com
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> (cherry picked from commit 73ea73affe8622bdf292de898da869d441da6a9d)
> ---
>  drivers/usb/gadget/udc/core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Why just a 5.10.y backport?  What about 5.15.y as well?  You can't
upgrade kernels and have a regression :(

thanks,

greg k-h

Re: [PATCH 5.10.y] USB: gadget: core: adjust uevent timing on gadget unbind

[Roy Luo]

On Mon, Dec 18, 2023 at 2:41 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> Why just a 5.10.y backport?  What about 5.15.y as well?  You can't
> upgrade kernels and have a regression :(

I was waiting for the 5.10 backport to be accepted before sending the
5.15 as this was my first time sending something to the stable tree
and I wasn't sure whether I got everything right.  Maybe I was being
too conservative.
I saw you've applied the patch to 5.15 as well, thanks for that!

Happy holiday!
Roy Luo