From 1ddc7618294084fff8d673217a9479550990ee84 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Mon, 23 Jan 2023 12:59:45 +0530 Subject: bus: mhi: ep: Change state_lock to mutex state_lock, the spinlock type is meant to protect race against concurrent MHI state transitions. In mhi_ep_set_m0_state(), while the state_lock is being held, the channels are resumed in mhi_ep_resume_channels() if the previous state was M3. This causes sleeping in atomic bug, since mhi_ep_resume_channels() use mutex internally. Since the state_lock is supposed to be held throughout the state change, it is not ideal to drop the lock before calling mhi_ep_resume_channels(). So to fix this issue, let's change the type of state_lock to mutex. This would also allow holding the lock throughout all state transitions thereby avoiding any potential race. Cc: # 5.19 Fixes: e4b7b5f0f30a ("bus: mhi: ep: Add support for suspending and resuming channels") Reported-by: Dan Carpenter Reviewed-by: Jeffrey Hugo Signed-off-by: Manivannan Sadhasivam --- include/linux/mhi_ep.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h index 478aece17046..f198a8ac7ee7 100644 --- a/include/linux/mhi_ep.h +++ b/include/linux/mhi_ep.h @@ -70,8 +70,8 @@ struct mhi_ep_db_info { * @cmd_ctx_cache_phys: Physical address of the host command context cache * @chdb: Array of channel doorbell interrupt info * @event_lock: Lock for protecting event rings - * @list_lock: Lock for protecting state transition and channel doorbell lists * @state_lock: Lock for protecting state transitions + * @list_lock: Lock for protecting state transition and channel doorbell lists * @st_transition_list: List of state transitions * @ch_db_list: List of queued channel doorbells * @wq: Dedicated workqueue for handling rings and state changes @@ -117,8 +117,8 @@ struct mhi_ep_cntrl { struct mhi_ep_db_info chdb[4]; struct mutex event_lock; + struct mutex state_lock; spinlock_t list_lock; - spinlock_t state_lock; struct list_head st_transition_list; struct list_head ch_db_list; -- cgit v1.2.3