diff options
| author | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2023-01-23 10:29:45 +0300 |
|---|---|---|
| committer | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2023-01-27 10:01:41 +0300 |
| commit | 1ddc7618294084fff8d673217a9479550990ee84 (patch) | |
| tree | a1c166517bd8d83b03148acd64d76d7d0cbf551a /drivers/bus/mhi/ep/main.c | |
| parent | 8a1c24bb908f9ecbc4be0fea014df67d43161551 (diff) | |
| download | linux-1ddc7618294084fff8d673217a9479550990ee84.tar.xz | |
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: <stable@vger.kernel.org> # 5.19
Fixes: e4b7b5f0f30a ("bus: mhi: ep: Add support for suspending and resuming channels")
Reported-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Diffstat (limited to 'drivers/bus/mhi/ep/main.c')
| -rw-r--r-- | drivers/bus/mhi/ep/main.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index bcaaba97ef63..528c00b232bf 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -1001,11 +1001,11 @@ static void mhi_ep_reset_worker(struct work_struct *work) mhi_ep_power_down(mhi_cntrl); - spin_lock_bh(&mhi_cntrl->state_lock); + 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); cur_state = mhi_cntrl->mhi_state; - spin_unlock_bh(&mhi_cntrl->state_lock); /* * Only proceed further if the reset is due to SYS_ERR. The host will @@ -1014,6 +1014,8 @@ 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); } /* @@ -1386,8 +1388,8 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, INIT_LIST_HEAD(&mhi_cntrl->st_transition_list); INIT_LIST_HEAD(&mhi_cntrl->ch_db_list); - spin_lock_init(&mhi_cntrl->state_lock); spin_lock_init(&mhi_cntrl->list_lock); + mutex_init(&mhi_cntrl->state_lock); mutex_init(&mhi_cntrl->event_lock); /* Set MHI version and AMSS EE before enumeration */ |