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Mon, 13 Apr 2026 23:29:50 -0700 (PDT) Received: from hu-sumk-hyd.qualcomm.com ([202.46.23.25]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82f0c50d40bsm12964090b3a.58.2026.04.13.23.29.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Apr 2026 23:29:49 -0700 (PDT) From: Sumit Kumar Date: Tue, 14 Apr 2026 11:59:40 +0530 Subject: [PATCH v2 1/2] bus: mhi: ep: Fix potential deadlock in mhi_ep_reset_worker() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260414-reset_worker_deadlock-v2-1-42fd682b45db@oss.qualcomm.com> References: <20260414-reset_worker_deadlock-v2-0-42fd682b45db@oss.qualcomm.com> In-Reply-To: <20260414-reset_worker_deadlock-v2-0-42fd682b45db@oss.qualcomm.com> To: Manivannan Sadhasivam , Alex Elder , Greg Kroah-Hartman Cc: mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Veerabhadrarao Badiganti , Subramanian Ananthanarayanan , Akhil Vinod , Sumit Kumar X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; 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The lock is only needed to protect current MHI state read operation. The lock can be safely released before proceeding with the power up sequence. Fixes: 7a97b6b47353 ("bus: mhi: ep: Add support for handling MHI_RESET") Signed-off-by: Sumit Kumar --- drivers/bus/mhi/ep/main.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index cdea24e9291959ae0a92487c1b9698dc8164d2f1..4bb007d1933315e5b0b40d235248d5373548d3f4 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -1087,11 +1087,12 @@ static void mhi_ep_reset_worker(struct work_struct *work) mhi_ep_power_down(mhi_cntrl); - mutex_lock(&mhi_cntrl->state_lock); - /* Reset MMIO to signal host that the MHI_RESET is completed in endpoint */ mhi_ep_mmio_reset(mhi_cntrl); + + mutex_lock(&mhi_cntrl->state_lock); cur_state = mhi_cntrl->mhi_state; + mutex_unlock(&mhi_cntrl->state_lock); /* * Only proceed further if the reset is due to SYS_ERR. The host will @@ -1100,8 +1101,6 @@ static void mhi_ep_reset_worker(struct work_struct *work) */ if (cur_state == MHI_STATE_SYS_ERR) mhi_ep_power_up(mhi_cntrl); - - mutex_unlock(&mhi_cntrl->state_lock); } /* -- 2.34.1