From: Oliver Neukum <oneukum@suse.com>
To: Hongyu Xie <xiehongyu1@kylinos.cn>, gregkh@linuxfoundation.org
Cc: brauner@kernel.org, jlayton@kernel.org, jack@suse.cz,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH next] usb: usbfs: Add reset_resume for usbfs
Date: Thu, 11 Jul 2024 10:59:56 +0200 [thread overview]
Message-ID: <527927b8-9475-47da-bf2b-7a5d9e81e470@suse.com> (raw)
In-Reply-To: <20240711084321.44916-1-xiehongyu1@kylinos.cn>
On 11.07.24 10:43, Hongyu Xie wrote:
> During hibernation, usb_resume_interface will set needs_binding to 1 if
> the usb_driver has no reset_resume implimentation. The USB interface
> will be rebind after usb_resume_complete.
>
> Normally, that's fine. But if a USB interface has a matched kernel
> driver, and a userspace driver or application is using this USB
> interface through usbfs during hibernation, usbfs will be
> detatched with the USB interface after resume. And this USB interface
> will be bind with a kernel driver instead of usbfs.
>
> So add reset_resume to fix this.
The device has lost all settings, yet we continue like nothing
changed. That strikes me as a very bad idea. If a device has undergone
a reset user space has not requested, we need to return an error upon
the next interaction.
I am sorry, but this implementation has some fundamental issues.
Regards
Oliver
next prev parent reply other threads:[~2024-07-11 9:00 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-11 8:43 Hongyu Xie
2024-07-11 8:59 ` Oliver Neukum [this message]
2024-07-11 14:41 ` Alan Stern
2024-07-15 8:53 ` Oliver Neukum
2024-07-15 14:22 ` Alan Stern
2024-07-16 12:44 ` Oliver Neukum
2024-07-17 1:43 ` Hongyu Xie
2024-07-17 2:05 ` Alan Stern
2024-07-17 3:13 ` Hongyu Xie
2024-07-17 7:52 ` Oliver Neukum
2024-07-17 13:44 ` Alan Stern
2024-07-17 15:27 ` Oliver Neukum
2024-07-17 7:42 ` Oliver Neukum
2024-07-18 3:23 ` Hongyu Xie
2024-07-12 3:10 ` Hongyu Xie
2024-07-13 2:22 ` Alan Stern
2024-07-15 1:13 ` Hongyu Xie
2024-07-15 8:40 ` Oliver Neukum
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