From: Alan Stern <stern@rowland.harvard.edu>
To: Badhri Jagan Sridharan <badhri@google.com>
Cc: gregkh@linuxfoundation.org, colin.i.king@gmail.com,
xuetao09@huawei.com, quic_eserrao@quicinc.com,
water.zhangjiantao@huawei.com, peter.chen@freescale.com,
balbi@ti.com, francesco@dolcini.it, alistair@alistair23.me,
stephan@gerhold.net, bagasdotme@gmail.com, luca@z3ntu.xyz,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org,
Francesco Dolcini <francesco.dolcini@toradex.com>
Subject: Re: [PATCH v1] usb: gadget: udc: core: Offload usb_udc_vbus_handler processing
Date: Wed, 17 May 2023 10:44:53 -0400 [thread overview]
Message-ID: <c7f19b4e-469c-4e40-bd2e-e864ca5f7872@rowland.harvard.edu> (raw)
In-Reply-To: <20230517115955.1078339-1-badhri@google.com>
On Wed, May 17, 2023 at 11:59:55AM +0000, Badhri Jagan Sridharan wrote:
> chipidea udc calls usb_udc_vbus_handler from udc_start gadget
> ops causing a deadlock. Avoid this by offloading usb_udc_vbus_handler
> processing.
Surely that is the wrong approach.
The real problem here is that usb_udc_vbus_handler() gets called from
within a udc_start routine. But this is totally unnecessary, because
the UDC core will call usb_udc_connect_control_locked() itself, later on
during gadget_bind_driver().
So a proper solution would be simply to remove the unnecessary
usb_udc_vbus_handler() call from the chipidea driver (and similarly for
the max3420_udc driver).
Similar changes may be needed in these drivers' udc_stop routines.
Alan Stern
next prev parent reply other threads:[~2023-05-17 14:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-17 11:59 Badhri Jagan Sridharan
2023-05-17 12:04 ` Badhri Jagan Sridharan
2023-05-17 14:44 ` Alan Stern [this message]
2023-05-17 17:19 ` Badhri Jagan Sridharan
2023-05-17 20:01 ` Alan Stern
2023-05-19 4:29 ` Badhri Jagan Sridharan
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