From: Sumit Kumar Date: Tue, 14 Apr 2026 06:29:40 +0000 (+0530) Subject: bus: mhi: ep: Fix potential deadlock in mhi_ep_reset_worker() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9dece4435d396e9877e27483552b910ba8654169;p=thirdparty%2Flinux.git bus: mhi: ep: Fix potential deadlock in mhi_ep_reset_worker() There is a potential deadlock scenario in mhi_ep_reset_worker() where the state_lock mutex is acquired twice in the same call chain: mhi_ep_reset_worker() mutex_lock(&mhi_cntrl->state_lock) mhi_ep_power_up() mhi_ep_set_ready_state() mutex_lock(&mhi_cntrl->state_lock) <- Deadlock Fix this by releasing the state_lock before calling mhi_ep_power_up(). 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 Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20260414-reset_worker_deadlock-v2-1-42fd682b45db@oss.qualcomm.com --- diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index 0277e1ab11988..425525e232f91 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); } /*