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From: xiaoxiao_li <lxxstone@gmail.com>
To: gregkh@linuxfoundation.org
Cc: hminas@synopsys.com, linux-kernel@vger.kernel.org,
	linux-usb@vger.kernel.org, lxxstone@gmail.com
Subject: Re: [PATCH] usb: dwc2: exit clock_gating when stopping udc caused deadlock
Date: Fri, 10 Apr 2026 11:36:07 +0800	[thread overview]
Message-ID: <20260410033607.3846202-1-lxxstone@gmail.com> (raw)
In-Reply-To: <2026031116-canine-blimp-94ae@gregkh>

Sorry for the unclear explanation.
This is caused by the patch modification ba78c2b3254c usb: dwc2: also exit clock_gating when stopping udc while suspended.

before this patch, the dwc2_gadget_exit_clock_gating was used in the IRQ handler,
and the handler would immediately acquire the lock with a spin_lock upon entering the function.
However, dwc2_gadget_exit_clock_gating do unlocks first and then relocks after done.
This modification is used in a normal flow, causing a deadlock to occur whenever this function is called.

      reply	other threads:[~2026-04-10  3:36 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-10  8:00 [PATCH] usb: dwc2: exit clock_gating when stopping udc caused deadlock xiaoxiao_li
2026-03-11 14:17 ` Greg KH
2026-04-10  3:36   ` xiaoxiao_li [this message]

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