On 05/07/2018 08:06 PM, Mauro Carvalho Chehab wrote:
> Em Thu, 3 May 2018 16:53:02 +0200
> Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
>
>> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>>
>> Integrate the request support. This adds the v4l2_ctrl_request_complete
>> and v4l2_ctrl_request_setup functions to complete a request and (as a
>> helper function) to apply a request to the hardware.
>>
>> It takes care of queuing requests and correctly chaining control values
>> in the request queue.
>>
>> Note that when a request is marked completed it will copy control values
>> to the internal request state. This can be optimized in the future since
>> this is sub-optimal when dealing with large compound and/or array controls.
>>
>> For the initial 'stateless codec' use-case the current implementation is
>> sufficient.
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>> ---
>> drivers/media/v4l2-core/v4l2-ctrls.c | 331 ++++++++++++++++++++++++++-
>> include/media/v4l2-ctrls.h | 23 ++
>> 2 files changed, 348 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
>> index da4cc1485dc4..56b986185463 100644
>> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
>> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
>> @@ -1647,6 +1647,13 @@ static int new_to_user(struct v4l2_ext_control *c,
>> return ptr_to_user(c, ctrl, ctrl->p_new);
>> }
>>
>> +/* Helper function: copy the request value back to the caller */
>> +static int req_to_user(struct v4l2_ext_control *c,
>> + struct v4l2_ctrl_ref *ref)
>> +{
>> + return ptr_to_user(c, ref->ctrl, ref->p_req);
>> +}
>> +
>> /* Helper function: copy the initial control value back to the caller */
>> static int def_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
>> {
>> @@ -1766,6 +1773,26 @@ static void cur_to_new(struct v4l2_ctrl *ctrl)
>> ptr_to_ptr(ctrl, ctrl->p_cur, ctrl->p_new);
>> }
>>
>> +/* Copy the new value to the request value */
>> +static void new_to_req(struct v4l2_ctrl_ref *ref)
>> +{
>> + if (!ref)
>> + return;
>> + ptr_to_ptr(ref->ctrl, ref->ctrl->p_new, ref->p_req);
>> + ref->req = ref;
>> +}
>> +
>> +/* Copy the request value to the new value */
>> +static void req_to_new(struct v4l2_ctrl_ref *ref)
>> +{
>> + if (!ref)
>> + return;
>> + if (ref->req)
>> + ptr_to_ptr(ref->ctrl, ref->req->p_req, ref->ctrl->p_new);
>> + else
>> + ptr_to_ptr(ref->ctrl, ref->ctrl->p_cur, ref->ctrl->p_new);
>> +}
>> +
>> /* Return non-zero if one or more of the controls in the cluster has a new
>> value that differs from the current value. */
>> static int cluster_changed(struct v4l2_ctrl *master)
>> @@ -1875,6 +1902,9 @@ int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
>> lockdep_set_class_and_name(hdl->lock, key, name);
>> INIT_LIST_HEAD(&hdl->ctrls);
>> INIT_LIST_HEAD(&hdl->ctrl_refs);
>> + INIT_LIST_HEAD(&hdl->requests);
>> + INIT_LIST_HEAD(&hdl->requests_queued);
>> + hdl->request_is_queued = false;
>> hdl->nr_of_buckets = 1 + nr_of_controls_hint / 8;
>> hdl->buckets = kvmalloc_array(hdl->nr_of_buckets,
>> sizeof(hdl->buckets[0]),
>> @@ -1895,6 +1925,14 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
>> if (hdl == NULL || hdl->buckets == NULL)
>> return;
>>
>> + if (!hdl->req_obj.req && !list_empty(&hdl->requests)) {
>> + struct v4l2_ctrl_handler *req, *next_req;
>> +
>> + list_for_each_entry_safe(req, next_req, &hdl->requests, requests) {
>> + media_request_object_unbind(&req->req_obj);
>> + media_request_object_put(&req->req_obj);
>> + }
>> + }
>> mutex_lock(hdl->lock);
>> /* Free all nodes */
>> list_for_each_entry_safe(ref, next_ref, &hdl->ctrl_refs, node) {
>> @@ -2816,6 +2854,128 @@ int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm)
>> }
>> EXPORT_SYMBOL(v4l2_querymenu);
>>
>> +static int v4l2_ctrl_request_clone(struct v4l2_ctrl_handler *hdl,
>> + const struct v4l2_ctrl_handler *from)
>> +{
>> + struct v4l2_ctrl_ref *ref;
>> + int err;
>> +
>> + if (WARN_ON(!hdl || hdl == from))
>> + return -EINVAL;
>> +
>> + if (hdl->error)
>> + return hdl->error;
>> +
>> + WARN_ON(hdl->lock != &hdl->_lock);
>> +
>> + mutex_lock(from->lock);
>> + list_for_each_entry(ref, &from->ctrl_refs, node) {
>> + struct v4l2_ctrl *ctrl = ref->ctrl;
>> + struct v4l2_ctrl_ref *new_ref;
>> +
>> + /* Skip refs inherited from other devices */
>> + if (ref->from_other_dev)
>> + continue;
>> + /* And buttons */
>> + if (ctrl->type == V4L2_CTRL_TYPE_BUTTON)
>> + continue;
>> + err = handler_new_ref(hdl, ctrl, &new_ref, false, true);
>> + if (err) {
>> + printk("%s: handler_new_ref on control %x (%s) returned %d\n", __func__, ctrl->id, ctrl->name, err);
>> + err = 0;
>> + continue;
>> + }
>> + if (err)
>> + break;
>> + }
>> + mutex_unlock(from->lock);
>> + return err;
>> +}
>> +
>> +static void v4l2_ctrl_request_queue(struct media_request_object *obj)
>> +{
>> + struct v4l2_ctrl_handler *hdl =
>> + container_of(obj, struct v4l2_ctrl_handler, req_obj);
>> + struct v4l2_ctrl_handler *main_hdl = obj->priv;
>> + struct v4l2_ctrl_handler *prev_hdl = NULL;
>> + struct v4l2_ctrl_ref *ref_ctrl, *ref_ctrl_prev = NULL;
>> +
>> + if (list_empty(&main_hdl->requests_queued))
>> + goto queue;
>> +
>> + prev_hdl = list_last_entry(&main_hdl->requests_queued,
>> + struct v4l2_ctrl_handler, requests_queued);
>> + /*
>> + * Note: prev_hdl and hdl must contain the same list of control
>> + * references, so if any differences are detected then that is a
>> + * driver bug and the WARN_ON is triggered.
>> + */
>> + mutex_lock(prev_hdl->lock);
>> + ref_ctrl_prev = list_first_entry(&prev_hdl->ctrl_refs,
>> + struct v4l2_ctrl_ref, node);
>> + list_for_each_entry(ref_ctrl, &hdl->ctrl_refs, node) {
>> + if (ref_ctrl->req)
>> + continue;
>> + while (ref_ctrl_prev->ctrl->id < ref_ctrl->ctrl->id) {
>> + /* Should never happen, but just in case... */
>> + if (list_is_last(&ref_ctrl_prev->node,
>> + &prev_hdl->ctrl_refs))
>> + break;
>> + ref_ctrl_prev = list_next_entry(ref_ctrl_prev, node);
>> + }
>> + if (WARN_ON(ref_ctrl_prev->ctrl->id != ref_ctrl->ctrl->id))
>> + break;
>
> Hmm... if the WARN_ON() is issued, should it still be queuing it? If
> there's a driver's bug, I suspect it would be better to do, instead:
>
> if (WARN_ON(ref_ctrl_prev->ctrl->id != ref_ctrl->ctrl->id)) {
> mutex_unlock(prev_hdl->lock);
> return;
> }
Good point. I'll have to think about this a bit more.
>
>> + ref_ctrl->req = ref_ctrl_prev->req;
>> + }
>> + mutex_unlock(prev_hdl->lock);
>> +queue:
>> + list_add_tail(&hdl->requests_queued, &main_hdl->requests_queued);
>> + hdl->request_is_queued = true;
>> +}
>> +
>> +static void v4l2_ctrl_request_unbind(struct media_request_object *obj)
>> +{
>> + struct v4l2_ctrl_handler *hdl =
>> + container_of(obj, struct v4l2_ctrl_handler, req_obj);
>> +
>> + list_del_init(&hdl->requests);
>> + if (hdl->request_is_queued) {
>> + list_del_init(&hdl->requests_queued);
>> + hdl->request_is_queued = false;
>> + }
>> +}
>> +
>> +static void v4l2_ctrl_request_release(struct media_request_object *obj)
>> +{
>> + struct v4l2_ctrl_handler *hdl =
>> + container_of(obj, struct v4l2_ctrl_handler, req_obj);
>> +
>> + v4l2_ctrl_handler_free(hdl);
>> + kfree(hdl);
>> +}
>> +
>> +static const struct media_request_object_ops req_ops = {
>> + .queue = v4l2_ctrl_request_queue,
>> + .unbind = v4l2_ctrl_request_unbind,
>> + .release = v4l2_ctrl_request_release,
>> +};
>> +
>> +static int v4l2_ctrl_request_bind(struct media_request *req,
>> + struct v4l2_ctrl_handler *hdl,
>> + struct v4l2_ctrl_handler *from)
>> +{
>> + int ret;
>> +
>> + ret = v4l2_ctrl_request_clone(hdl, from);
>> +
>> + if (!ret) {
>> + ret = media_request_object_bind(req, &req_ops,
>> + from, &hdl->req_obj);
>> + if (!ret)
>> + list_add_tail(&hdl->requests, &from->requests);
>> + }
>> + return ret;
>> +}
>>
>> /* Some general notes on the atomic requirements of VIDIOC_G/TRY/S_EXT_CTRLS:
>>
>> @@ -2877,6 +3037,7 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
>>
>> if (cs->which &&
>> cs->which != V4L2_CTRL_WHICH_DEF_VAL &&
>> + cs->which != V4L2_CTRL_WHICH_REQUEST_VAL &&
>> V4L2_CTRL_ID2WHICH(id) != cs->which)
>> return -EINVAL;
>>
>> @@ -2956,13 +3117,12 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
>> whether there are any controls at all. */
>> static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
>> {
>> - if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL)
>> + if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL ||
>> + which == V4L2_CTRL_WHICH_REQUEST_VAL)
>> return 0;
>> return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
>> }
>>
>> -
>> -
>> /* Get extended controls. Allocates the helpers array if needed. */
>> int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
>> {
>> @@ -3028,8 +3188,12 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
>> u32 idx = i;
>>
>> do {
>> - ret = ctrl_to_user(cs->controls + idx,
>> - helpers[idx].ref->ctrl);
>> + if (helpers[idx].ref->req)
>> + ret = req_to_user(cs->controls + idx,
>> + helpers[idx].ref->req);
>> + else
>> + ret = ctrl_to_user(cs->controls + idx,
>> + helpers[idx].ref->ctrl);
>> idx = helpers[idx].next;
>> } while (!ret && idx);
>> }
>> @@ -3302,7 +3466,16 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
>> } while (!ret && idx);
>>
>> if (!ret)
>> - ret = try_or_set_cluster(fh, master, set, 0);
>> + ret = try_or_set_cluster(fh, master,
>> + !hdl->req_obj.req && set, 0);
>> + if (!ret && hdl->req_obj.req && set) {
>> + for (j = 0; j < master->ncontrols; j++) {
>> + struct v4l2_ctrl_ref *ref =
>> + find_ref(hdl, master->cluster[j]->id);
>> +
>> + new_to_req(ref);
>> + }
>> + }
>>
>> /* Copy the new values back to userspace. */
>> if (!ret) {
>> @@ -3429,6 +3602,152 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
>> }
>> EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_string);
>>
>> +void v4l2_ctrl_request_complete(struct media_request *req,
>> + struct v4l2_ctrl_handler *main_hdl)
>> +{
>> + struct media_request_object *obj;
>> + struct v4l2_ctrl_handler *hdl;
>> + struct v4l2_ctrl_ref *ref;
>> +
>> + if (!req || !main_hdl)
>> + return;
>> +
>> + obj = media_request_object_find(req, &req_ops, main_hdl);
>> + if (!obj)
>> + return;
>> + hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);
>> +
>> + list_for_each_entry(ref, &hdl->ctrl_refs, node) {
>> + struct v4l2_ctrl *ctrl = ref->ctrl;
>> + struct v4l2_ctrl *master = ctrl->cluster[0];
>> + unsigned int i;
>> +
>> + if (ctrl->flags & V4L2_CTRL_FLAG_VOLATILE) {
>> + ref->req = ref;
>> +
>> + v4l2_ctrl_lock(master);
>> + /* g_volatile_ctrl will update the current control values */
>> + for (i = 0; i < master->ncontrols; i++)
>> + cur_to_new(master->cluster[i]);
>> + call_op(master, g_volatile_ctrl);
>> + new_to_req(ref);
>> + v4l2_ctrl_unlock(master);
>> + continue;
>> + }
>> + if (ref->req == ref)
>> + continue;
>> +
>> + v4l2_ctrl_lock(ctrl);
>> + if (ref->req)
>> + ptr_to_ptr(ctrl, ref->req->p_req, ref->p_req);
>> + else
>> + ptr_to_ptr(ctrl, ctrl->p_cur, ref->p_req);
>> + v4l2_ctrl_unlock(ctrl);
>> + }
>> +
>> + WARN_ON(!hdl->request_is_queued);
>> + list_del_init(&hdl->requests_queued);
>> + hdl->request_is_queued = false;
>> + media_request_object_complete(obj);
>> + media_request_object_put(obj);
>> +}
>> +EXPORT_SYMBOL(v4l2_ctrl_request_complete);
>> +
>> +void v4l2_ctrl_request_setup(struct media_request *req,
>> + struct v4l2_ctrl_handler *main_hdl)
>> +{
>> + struct media_request_object *obj;
>> + struct v4l2_ctrl_handler *hdl;
>> + struct v4l2_ctrl_ref *ref;
>> +
>> + if (!req || !main_hdl)
>> + return;
>> +
>> + obj = media_request_object_find(req, &req_ops, main_hdl);
>> + if (!obj)
>> + return;
>> + if (obj->completed) {
>> + media_request_object_put(obj);
>> + return;
>> + }
>> + hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);
>> +
>> + mutex_lock(hdl->lock);
>> +
>> + list_for_each_entry(ref, &hdl->ctrl_refs, node)
>> + ref->done = false;
>> +
>> + list_for_each_entry(ref, &hdl->ctrl_refs, node) {
>> + struct v4l2_ctrl *ctrl = ref->ctrl;
>> + struct v4l2_ctrl *master = ctrl->cluster[0];
>> + bool have_new_data = false;
>> + int i;
>> +
>> + /*
>> + * Skip if this control was already handled by a cluster.
>> + * Skip button controls and read-only controls.
>> + */
>> + if (ref->done || ctrl->type == V4L2_CTRL_TYPE_BUTTON ||
>> + (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY))
>> + continue;
>> +
>> + v4l2_ctrl_lock(master);
>> + for (i = 0; i < master->ncontrols; i++) {
>> + if (master->cluster[i]) {
>> + struct v4l2_ctrl_ref *r =
>> + find_ref(hdl, master->cluster[i]->id);
>> +
>> + if (r->req && r == r->req) {
>> + have_new_data = true;
>> + break;
>> + }
>> + }
>> + }
>> + if (!have_new_data) {
>> + v4l2_ctrl_unlock(master);
>> + continue;
>> + }
>> +
>> + for (i = 0; i < master->ncontrols; i++) {
>> + if (master->cluster[i]) {
>> + struct v4l2_ctrl_ref *r =
>> + find_ref(hdl, master->cluster[i]->id);
>> +
>> + req_to_new(r);
>> + master->cluster[i]->is_new = 1;
>> + r->done = true;
>> + }
>> + }
>> + /*
>> + * For volatile autoclusters that are currently in auto mode
>> + * we need to discover if it will be set to manual mode.
>> + * If so, then we have to copy the current volatile values
>> + * first since those will become the new manual values (which
>> + * may be overwritten by explicit new values from this set
>> + * of controls).
>> + */
>> + if (master->is_auto && master->has_volatiles &&
>> + !is_cur_manual(master)) {
>> + s32 new_auto_val = *master->p_new.p_s32;
>> +
>> + /*
>> + * If the new value == the manual value, then copy
>> + * the current volatile values.
>> + */
>> + if (new_auto_val == master->manual_mode_value)
>> + update_from_auto_cluster(master);
>> + }
>> +
>> + try_or_set_cluster(NULL, master, true, 0);
>> +
>> + v4l2_ctrl_unlock(master);
>> + }
>> +
>> + mutex_unlock(hdl->lock);
>> + media_request_object_put(obj);
>> +}
>> +EXPORT_SYMBOL(v4l2_ctrl_request_setup);
>> +
>> void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv)
>> {
>> if (ctrl == NULL)
>> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
>> index 76352eb59f14..a0f7c38d1a90 100644
>> --- a/include/media/v4l2-ctrls.h
>> +++ b/include/media/v4l2-ctrls.h
>> @@ -250,6 +250,10 @@ struct v4l2_ctrl {
>> * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
>> * @from_other_dev: If true, then @ctrl was defined in another
>> * device than the &struct v4l2_ctrl_handler.
>> + * @done: If true, then this control reference is part of a
>> + * control cluster that was already set while applying
>> + * the controls in this media request object.
>
> Hmm... I would rename it for request_done or something similar, as it
> seems that this applies only for requests.
No, the variable name is correct (it serves the same purpose as the 'done'
field in struct v4l2_ctrl), but the description should be improved.
I also want to take another look at this: I wonder if it isn't possible to
use the v4l2_ctrl 'done' field for this instead of having to add a new field
here.
>
>> + * @req: If set, this refers to another request that sets this control.
>> * @p_req: The request value. Only used if the control handler
>> * is bound to a media request.
>> *
>> @@ -263,6 +267,8 @@ struct v4l2_ctrl_ref {
>> struct v4l2_ctrl *ctrl;
>> struct v4l2_ctrl_helper *helper;
>> bool from_other_dev;
>> + bool done;
>> + struct v4l2_ctrl_ref *req;
>> union v4l2_ctrl_ptr p_req;
>> };
>>
>> @@ -287,6 +293,15 @@ struct v4l2_ctrl_ref {
>> * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
>> * @nr_of_buckets: Total number of buckets in the array.
>> * @error: The error code of the first failed control addition.
>> + * @request_is_queued: True if the request was queued.
>> + * @requests: List to keep track of open control handler request objects.
>> + * For the parent control handler (@req_obj.req == NULL) this
>> + * is the list header. When the parent control handler is
>> + * removed, it has to unbind and put all these requests since
>> + * they refer to the parent.
>> + * @requests_queued: List of the queued requests. This determines the order
>> + * in which these controls are applied. Once the request is
>> + * completed it is removed from this list.
>> * @req_obj: The &struct media_request_object, used to link into a
>> * &struct media_request.
>> */
>> @@ -301,6 +316,9 @@ struct v4l2_ctrl_handler {
>> void *notify_priv;
>> u16 nr_of_buckets;
>> int error;
>> + bool request_is_queued;
>> + struct list_head requests;
>> + struct list_head requests_queued;
>> struct media_request_object req_obj;
>> };
>>
>> @@ -1059,6 +1077,11 @@ int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
>> */
>> __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
>>
>> +void v4l2_ctrl_request_setup(struct media_request *req,
>> + struct v4l2_ctrl_handler *hdl);
>> +void v4l2_ctrl_request_complete(struct media_request *req,
>> + struct v4l2_ctrl_handler *hdl);
>> +
>> /* Helpers for ioctl_ops */
>>
>> /**
>
>
>
> Thanks,
> Mauro
>
Regards,
Hans
