Merge "msm: camera: reqmgr: Prevent session deadlock" into camera-kernel.lnx.5.0

This commit is contained in:
Camera Software Integration
2021-09-03 14:29:48 -07:00
zatwierdzone przez Gerrit - the friendly Code Review server

Wyświetl plik

@@ -1424,20 +1424,20 @@ static int __cam_req_mgr_process_req(struct cam_req_mgr_core_link *link,
return -EINVAL;
}
mutex_lock(&session->lock);
/*
* In case if the wq is scheduled while destroying session
* the session mutex is already taken and will cause a
* dead lock. To avoid further processing check link state
* and exit.
* During session destroy/unlink the link state is updated and session
* mutex is released when flushing the workq. In case the wq is scheduled
* thereafter this API will then check the updated link state and exit
*/
spin_lock_bh(&link->link_state_spin_lock);
if (link->state == CAM_CRM_LINK_STATE_IDLE) {
spin_unlock_bh(&link->link_state_spin_lock);
mutex_unlock(&session->lock);
return -EPERM;
}
spin_unlock_bh(&link->link_state_spin_lock);
mutex_lock(&session->lock);
in_q = link->req.in_q;
/*
* Check if new read index,
@@ -4460,13 +4460,17 @@ end:
/**
* __cam_req_mgr_unlink()
*
* @brief : Unlink devices on a link structure from the session
* @link : Pointer to the link structure
* @brief : Unlink devices on a link structure from the session
* This API is to be invoked with session mutex held
* @session: session of the link
* @link : Pointer to the link structure
*
* @return: 0 for success, negative for failure
*
*/
static int __cam_req_mgr_unlink(struct cam_req_mgr_core_link *link)
static int __cam_req_mgr_unlink(
struct cam_req_mgr_core_session *session,
struct cam_req_mgr_core_link *link)
{
int rc;
@@ -4482,14 +4486,16 @@ static int __cam_req_mgr_unlink(struct cam_req_mgr_core_link *link)
}
mutex_lock(&link->lock);
spin_lock_bh(&link->link_state_spin_lock);
/* Destroy timer of link */
crm_timer_exit(&link->watchdog);
spin_unlock_bh(&link->link_state_spin_lock);
/* Release session mutex for workq processing */
mutex_unlock(&session->lock);
/* Destroy workq of link */
cam_req_mgr_workq_destroy(&link->workq);
/* Acquire session mutex after workq flush */
mutex_lock(&session->lock);
/* Cleanup request tables and unlink devices */
__cam_req_mgr_destroy_link_info(link);
/* Free memory holding data of linked devs */
@@ -4531,6 +4537,7 @@ int cam_req_mgr_destroy_session(
goto end;
}
mutex_lock(&cam_session->lock);
if (cam_session->num_links) {
CAM_DBG(CAM_CRM, "destroy session %x num_active_links %d",
@@ -4546,7 +4553,7 @@ int cam_req_mgr_destroy_session(
link->link_hdl);
/* Ignore return value since session is going away */
link->is_shutdown = is_shutdown;
__cam_req_mgr_unlink(link);
__cam_req_mgr_unlink(cam_session, link);
__cam_req_mgr_free_link(link);
}
}
@@ -4829,8 +4836,9 @@ int cam_req_mgr_unlink(struct cam_req_mgr_unlink_info *unlink_info)
rc = -EINVAL;
goto done;
}
rc = __cam_req_mgr_unlink(link);
mutex_lock(&cam_session->lock);
rc = __cam_req_mgr_unlink(cam_session, link);
mutex_unlock(&cam_session->lock);
/* Free curent link and put back into session's free pool of links */
__cam_req_mgr_unreserve_link(cam_session, link);