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[61.216.20.61]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-c7921a1ef00sm793446a12.28.2026.04.09.20.36.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2026 20:36:11 -0700 (PDT) From: xiaoxiao_li 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 Message-ID: <20260410033607.3846202-1-lxxstone@gmail.com> X-Mailer: git-send-email @GIT_VERSION@ In-Reply-To: <2026031116-canine-blimp-94ae@gregkh> References: <2026031116-canine-blimp-94ae@gregkh> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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.