Re: [PATCH] media: staging: rkisp1: cap: refactor enable/disable stream to allow multistreaming

From: Helen Koike
Date: Fri Oct 16 2020 - 14:14:01 EST


Hi Tomasz.

On 10/16/20 11:53 AM, Tomasz Figa wrote:
> On Fri, Oct 16, 2020 at 4:28 PM Dafna Hirschfeld
> <dafna.hirschfeld@xxxxxxxxxxxxx> wrote:
>>
>> Hi,
>>
>> Am 15.10.20 um 21:57 schrieb Helen Koike:
>>> Allow streaming from self picture path and main picture path at the same
>>> time.
>>>
>>> Take care for s_stream() callbacks to not be called twice.
>>> When starting a stream, s_stream(true) shouldn't be called for the isp
>>> and the sensor if the other stream is already enabled (since it was
>>> already called).
>>> When stopping a stream, s_stream(false) shouldn't be called for isp and
>>> the sensor if the other stream is still enabled.
>>>
>>> Remove the callback function scheme for navigating through the topology,
>>> simplifying the code, improving readability, while calling
>>> media_pipeline_{start,stop}() in the right order.
>>>
>>> Remove multistreaming item from the TODO list.
>>>
>>> Signed-off-by: Helen Koike <helen.koike@xxxxxxxxxxxxx>
>>>
>>> ---
>>> Hello,
>>>
>>> Since we didn't reach an agreement on the helpers in the core[1], I'm
>>> sending this patch to fix this limitation only for rkisp1.
>>>
>>> [1] https://patchwork.linuxtv.org/project/linux-media/cover/20200415013044.1778572-1-helen.koike@xxxxxxxxxxxxx/
>>>
>>> If we decide to add the helpers in the future, we can clean up drivers
>>> even more, but I don't want to block this feature.
>>>
>>> Overview of the patch:
>>> ======================
>>>
>>> * Rename rkisp1_stream_{start,stop}() to
>>> rkisp1_cap_stream_{enable,disable}() to clarify the difference between
>>> other stream enable/disable functions
>>>
>>> * Implement rkisp1_pipeline_stream_{enable,disable}() to replace
>>> rkisp1_pipeline_{enable,disable}_cb() and rkisp1_pipeline_sink_walk(),
>>> which were removed.
>>>
>>> * Call rkisp1_cap_stream_{enable,disable}() from
>>> rkisp1_pipeline_stream_{enable,disable}() for better
>>> unwind handling and function name semantics.
>>>
>>> * Call media_pipeline_{start,stop}() in the right order.
>>>
>>> * Remove item from TODO list (I also reviewed the use of the
>>> is_streaming var in the code and lgtm).
>>>
>>> This patch was tested on rockpi4 board with:
>>> ============================================
>>>
>>> "media-ctl" "-d" "platform:rkisp1" "-r"
>>> "media-ctl" "-d" "platform:rkisp1" "-l" "'imx219 4-0010':0 -> 'rkisp1_isp':0 [1]"
>>> "media-ctl" "-d" "platform:rkisp1" "-l" "'rkisp1_isp':2 -> 'rkisp1_resizer_selfpath':0 [1]"
>>> "media-ctl" "-d" "platform:rkisp1" "-l" "'rkisp1_isp':2 -> 'rkisp1_resizer_mainpath':0 [1]"
>>>
>>> "media-ctl" "-d" "platform:rkisp1" "--set-v4l2" '"imx219 4-0010":0 [fmt:SRGGB10_1X10/1640x1232]'
>>>
>>> "media-ctl" "-d" "platform:rkisp1" "--set-v4l2" '"rkisp1_isp":0 [fmt:SRGGB10_1X10/1640x1232 crop: (0,0)/1600x1200]'
>>> "media-ctl" "-d" "platform:rkisp1" "--set-v4l2" '"rkisp1_isp":2 [fmt:YUYV8_2X8/1600x1200 crop: (0,0)/1500x1100]'
>>>
>>> "media-ctl" "-d" "platform:rkisp1" "--set-v4l2" '"rkisp1_resizer_selfpath":0 [fmt:YUYV8_2X8/1500x1100 crop: (300,400)/1400x1000]'
>>> "media-ctl" "-d" "platform:rkisp1" "--set-v4l2" '"rkisp1_resizer_selfpath":1 [fmt:YUYV8_2X8/900x800]'
>>>
>>> "v4l2-ctl" "-z" "platform:rkisp1" "-d" "rkisp1_selfpath" "-v" "width=900,height=800,"
>>> "v4l2-ctl" "-z" "platform:rkisp1" "-d" "rkisp1_selfpath" "-v" "pixelformat=422P"
>>>
>>> "media-ctl" "-d" "platform:rkisp1" "--set-v4l2" '"rkisp1_resizer_mainpath":0 [fmt:YUYV8_2X8/1500x1100 crop: (300,400)/1400x1000]'
>>> "media-ctl" "-d" "platform:rkisp1" "--set-v4l2" '"rkisp1_resizer_mainpath":1 [fmt:YUYV8_2X8/900x800]'
>>>
>>> "v4l2-ctl" "-z" "platform:rkisp1" "-d" "rkisp1_mainpath" "-v" "width=900,height=800,"
>>> "v4l2-ctl" "-z" "platform:rkisp1" "-d" "rkisp1_mainpath" "-v" "pixelformat=422P"
>>>
>>> sleep 1
>>>
>>> time v4l2-ctl "-z" "platform:rkisp1" "-d" "rkisp1_mainpath" "--stream-mmap" "--stream-count" "100" &
>>> time v4l2-ctl "-z" "platform:rkisp1" "-d" "rkisp1_selfpath" "--stream-mmap" "--stream-count" "100" &
>>>
>>> wait
>>> echo "Completed"
>>>
>>> Thanks
>>> Helen
>>> ---
>>> drivers/staging/media/rkisp1/TODO | 3 -
>>> drivers/staging/media/rkisp1/rkisp1-capture.c | 227 +++++++++---------
>>> 2 files changed, 113 insertions(+), 117 deletions(-)
>>>
>>> diff --git a/drivers/staging/media/rkisp1/TODO b/drivers/staging/media/rkisp1/TODO
>>> index e7c8398fc2cef..a2dd0ad951c25 100644
>>> --- a/drivers/staging/media/rkisp1/TODO
>>> +++ b/drivers/staging/media/rkisp1/TODO
>>> @@ -1,9 +1,6 @@
>>> * Fix pad format size for statistics and parameters entities.
>>> * Fix checkpatch errors.
>>> * Add uapi docs. Remember to add documentation of how quantization is handled.
>>> -* streaming paths (mainpath and selfpath) check if the other path is streaming
>>> -in several places of the code, review this, specially that it doesn't seem it
>>> -supports streaming from both paths at the same time.
>>>
>>> NOTES:
>>> * All v4l2-compliance test must pass.
>>> diff --git a/drivers/staging/media/rkisp1/rkisp1-capture.c b/drivers/staging/media/rkisp1/rkisp1-capture.c
>>> index b6f497ce3e95c..254936873c6c1 100644
>>> --- a/drivers/staging/media/rkisp1/rkisp1-capture.c
>>> +++ b/drivers/staging/media/rkisp1/rkisp1-capture.c
>>> @@ -830,71 +830,43 @@ static void rkisp1_return_all_buffers(struct rkisp1_capture *cap,
>>> }
>>>
>>> /*
>>> - * rkisp1_pipeline_sink_walk - Walk through the pipeline and call cb
>>> - * @from: entity at which to start pipeline walk
>>> - * @until: entity at which to stop pipeline walk
>>> - *
>>> - * Walk the entities chain starting at the pipeline video node and stop
>>> - * all subdevices in the chain.
>>> - *
>>> - * If the until argument isn't NULL, stop the pipeline walk when reaching the
>>> - * until entity. This is used to disable a partially started pipeline due to a
>>> - * subdev start error.
>>> + * Most of registers inside rockchip ISP1 have shadow register since
>>> + * they must be not be changed during processing a frame.
>>> + * Usually, each sub-module updates its shadow register after
>>> + * processing the last pixel of a frame.
>>> */
>>> -static int rkisp1_pipeline_sink_walk(struct media_entity *from,
>>> - struct media_entity *until,
>>> - int (*cb)(struct media_entity *from,
>>> - struct media_entity *curr))
>>> +static void rkisp1_cap_stream_enable(struct rkisp1_capture *cap)
>>> {
>>> - struct media_entity *entity = from;
>>> - struct media_pad *pad;
>>> - unsigned int i;
>>> - int ret;
>>> -
>>> - while (1) {
>>> - pad = NULL;
>>> - /* Find remote source pad */
>>> - for (i = 0; i < entity->num_pads; i++) {
>>> - struct media_pad *spad = &entity->pads[i];
>>> -
>>> - if (!(spad->flags & MEDIA_PAD_FL_SINK))
>>> - continue;
>>> - pad = media_entity_remote_pad(spad);
>>> - if (pad && is_media_entity_v4l2_subdev(pad->entity))
>>> - break;
>>> - }
>>> - if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
>>> - break;
>>> + struct rkisp1_device *rkisp1 = cap->rkisp1;
>>> + struct rkisp1_capture *other = &rkisp1->capture_devs[cap->id ^ 1];
>>>
>>> - entity = pad->entity;
>>> - if (entity == until)
>>> - break;
>>> + cap->ops->set_data_path(cap);
>>> + cap->ops->config(cap);
>>>
>>> - ret = cb(from, entity);
>>> - if (ret)
>>> - return ret;
>>> + /* Setup a buffer for the next frame */
>>> + spin_lock_irq(&cap->buf.lock);
>>> + rkisp1_set_next_buf(cap);
>>> + cap->ops->enable(cap);
>>> + /* It's safe to config ACTIVE and SHADOW regs for the
>>> + * first stream. While when the second is starting, do NOT
>>> + * force update because it also update the first one.
>>> + *
>>> + * The latter case would drop one more buf(that is 2) since
>>> + * there's not buf in shadow when the second FE received. This's
>>> + * also required because the second FE maybe corrupt especially
>>> + * when run at 120fps.
>>> + */
>>> + if (!other->is_streaming) {
>>> + /* force cfg update */
>>> + rkisp1_write(rkisp1,
>>> + RKISP1_CIF_MI_INIT_SOFT_UPD, RKISP1_CIF_MI_INIT);
>>> + rkisp1_set_next_buf(cap);
>>> }
>>> -
>>> - return 0;
>>> -}
>>> -
>>> -static int rkisp1_pipeline_disable_cb(struct media_entity *from,
>>> - struct media_entity *curr)
>>> -{
>>> - struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(curr);
>>> -
>>> - return v4l2_subdev_call(sd, video, s_stream, false);
>>> -}
>>> -
>>> -static int rkisp1_pipeline_enable_cb(struct media_entity *from,
>>> - struct media_entity *curr)
>>> -{
>>> - struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(curr);
>>> -
>>> - return v4l2_subdev_call(sd, video, s_stream, true);
>>> + spin_unlock_irq(&cap->buf.lock);
>>> + cap->is_streaming = true;
>>> }
>>>
>>> -static void rkisp1_stream_stop(struct rkisp1_capture *cap)
>>> +static void rkisp1_cap_stream_disable(struct rkisp1_capture *cap)
>>> {
>>> int ret;
>>>
>>> @@ -911,6 +883,81 @@ static void rkisp1_stream_stop(struct rkisp1_capture *cap)
>>> }
>>> }
>>>
>>> +/*
>>> + * rkisp1_pipeline_stream_disable - disable nodes in the pipeline
>>> + *
>>> + * Call s_stream(false) in the reverse order from
>>> + * rkisp1_pipeline_stream_enable() and disable the DMA engine.
>>> + * Should be called before media_pipeline_stop()
>>> + */
>>> +static void rkisp1_pipeline_stream_disable(struct rkisp1_capture *cap)
>>> + __must_hold(&cap->rkisp1->stream_lock)
>>> +{
>>> + struct rkisp1_device *rkisp1 = cap->rkisp1;
>>> +
>>> + rkisp1_cap_stream_disable(cap);
>>> +
>>> + /*
>>> + * If the other capture is streaming, isp and sensor nodes shouldn't
>>> + * be disabled, skip them.
>>> + */
>>> + if (rkisp1->pipe.streaming_count < 2) {
>>> + v4l2_subdev_call(rkisp1->active_sensor->sd, video, s_stream,
>>> + false);
>>> + v4l2_subdev_call(&rkisp1->isp.sd, video, s_stream, false);
>>> + }
>>> +
>>> + v4l2_subdev_call(&rkisp1->resizer_devs[cap->id].sd, video, s_stream,
>>> + false);
>>
>> I wonder if the order of the disable matters. If it should be from the sensor up to the
>> capture then we should call 'rkisp1_cap_stream_disable' at the end of this
>> function.
>
> According to our downstream code [1] and my recollection of discussion
> with Rockchip, the power up order was:
> - ISP
> - sensor
> - PHY
> and power down the opposite.
>
> That said, the sensor drivers we had didn't implement s_power and used
> runtime PM at streaming time, so I think in practice the order ended
> up as:
> - ISP,
> - PHY,
> - sensor.
>
> The streaming enable order [2] was:
> - ISP,
> - PHY,
> - sensor
> and disable:
> - PHY,
> - sensor,
> - ISP.
>
> It's possible that the powering order probably was irrelevant and just
> the streaming itself is important or actually it doesn't matter. Some
> testing would be appreciated.
>
> [1] https://source.chromium.org/chromiumos/chromiumos/codesearch/+/master:src/third_party/kernel/v4.4/drivers/media/platform/rockchip/isp1/dev.c;drc=4372c82fc2f0d63b4fbb5390e72464709f8a34e9;l=110
> [2] https://source.chromium.org/chromiumos/chromiumos/codesearch/+/master:src/third_party/kernel/v4.4/drivers/media/platform/rockchip/isp1/dev.c;drc=4372c82fc2f0d63b4fbb5390e72464709f8a34e9;l=175

Thanks for this info, I can do some tests.

Regards,
Helen

>
> Best regards,
> Tomasz
>