RE: [RESEND PATCH v0 3/5] wave5 : Support runtime suspend/resume.

[jackson.lee <jackson.lee@chipsnmedia.com>]

Hello Nicolas

Thanks for your review.

> Hi Jackson,
> 
> sorry for the the delay, my reply below.
> 
> Le lundi 26 février 2024 à 01:33 +0000, jackson.lee a écrit :
> > Hello Nicolas
> >
> [...]
> >
> > I have added the autosuspend feature, can you please review the below
> code ?
> > If there is no problem at your side, I will make a patch for upstream.
> >
> >
> > diff --git a/drivers/media/platform/chips-media/wave5/wave5-hw.c
> > b/drivers/media/platform/chips-media/wave5/wave5-hw.c
> > index 0b6386f31..2ba9e0f0e 100644
> > --- a/drivers/media/platform/chips-media/wave5/wave5-hw.c
> > +++ b/drivers/media/platform/chips-media/wave5/wave5-hw.c
> > @@ -1102,8 +1102,8 @@ int wave5_vpu_re_init(struct device *dev, u8 *fw,
> size_t size)
> >  	return setup_wave5_properties(dev);
> >  }
> >
> > -static int wave5_vpu_sleep_wake(struct device *dev, bool i_sleep_wake,
> const uint16_t *code,
> > -				size_t size)
> > +int wave5_vpu_sleep_wake(struct device *dev, bool i_sleep_wake, const
> uint16_t *code,
> > +			 size_t size)
> >  {
> >  	u32 reg_val;
> >  	struct vpu_buf *common_vb;
> > diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
> > b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
> > index 8b1417ece..4aea66483 100644
> > --- a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
> > +++ b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
> > @@ -5,6 +5,7 @@
> >   * Copyright (C) 2021-2023 CHIPS&MEDIA INC
> >   */
> >
> > +#include <linux/pm_runtime.h>
> >  #include "wave5-helper.h"
> >
> >  #define VPU_DEC_DEV_NAME "C&M Wave5 VPU decoder"
> > @@ -518,6 +519,8 @@ static void wave5_vpu_dec_finish_decode(struct
> vpu_instance *inst)
> >  	if (q_status.report_queue_count == 0 &&
> >  	    (q_status.instance_queue_count == 0 ||
> dec_info.sequence_changed)) {
> >  		dev_dbg(inst->dev->dev, "%s: finishing job.\n", __func__);
> > +		pm_runtime_mark_last_busy(inst->dev->dev);
> > +		pm_runtime_put_autosuspend(inst->dev->dev);
> >  		v4l2_m2m_job_finish(inst->v4l2_m2m_dev, m2m_ctx);
> >  	}
> >  }
> > @@ -1382,6 +1385,7 @@ static int wave5_vpu_dec_start_streaming(struct
> vb2_queue *q, unsigned int count
> >  	int ret = 0;
> >
> >  	dev_dbg(inst->dev->dev, "%s: type: %u\n", __func__, q->type);
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> >
> >  	v4l2_m2m_update_start_streaming_state(m2m_ctx, q);
> >
> > @@ -1389,7 +1393,6 @@ static int wave5_vpu_dec_start_streaming(struct
> vb2_queue *q, unsigned int count
> >  		struct dec_open_param open_param;
> >
> >  		memset(&open_param, 0, sizeof(struct dec_open_param));
> > -
> 
> I'd refrain from mixing style changes with the function changes. Just
> leave the empty line, is it harmless. There is other cases in your RFC.
> 
> >  		ret = wave5_vpu_dec_allocate_ring_buffer(inst);
> >  		if (ret)
> >  			goto return_buffers;
> > @@ -1425,13 +1428,14 @@ static int wave5_vpu_dec_start_streaming(struct
> vb2_queue *q, unsigned int count
> >  			}
> >  		}
> >  	}
> > -
> 
> There is a case were userspace may start streaming but never populate the
> queues. You should call pm_runtime_put_autosuspend() here for this reason.
> In most cases it won't suspend as there device_run() get called very
> shortly after, before the timeout expires.
> 
> >  	return ret;
> >
> >  free_bitstream_vbuf:
> >  	wave5_vdi_free_dma_memory(inst->dev, &inst->bitstream_vbuf);
> >  return_buffers:
> >  	wave5_return_bufs(q, VB2_BUF_STATE_QUEUED);
> > +	pm_runtime_mark_last_busy(inst->dev->dev);
> 
> For fast operations or synchronous errors, I believe its fine to skip the
> "mark_last_busy()" calls. This is resetting the timeout start time, but if
> the elapse time is really short, I'm pretty sure there is very little
> values in pushing it forward. Removing that call from error case,
> stream_start/stop should make the patch a little lighter.
> 
> I think overall your RFC is in the right direction, and this is good
> material for a V2.
> 
> regards,
> Nicolas
> 
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  	return ret;
> >  }
> >
> > @@ -1517,6 +1521,7 @@ static void wave5_vpu_dec_stop_streaming(struct
> vb2_queue *q)
> >  	bool check_cmd = TRUE;
> >
> >  	dev_dbg(inst->dev->dev, "%s: type: %u\n", __func__, q->type);
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> >
> >  	while (check_cmd) {
> >  		struct queue_status_info q_status;
> > @@ -1540,6 +1545,9 @@ static void wave5_vpu_dec_stop_streaming(struct
> vb2_queue *q)
> >  		streamoff_output(q);
> >  	else
> >  		streamoff_capture(q);
> > +
> > +	pm_runtime_mark_last_busy(inst->dev->dev);
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  }
> >
> >  static const struct vb2_ops wave5_vpu_dec_vb2_ops = { @@ -1626,7
> > +1634,7 @@ static void wave5_vpu_dec_device_run(void *priv)
> >  	int ret = 0;
> >
> >  	dev_dbg(inst->dev->dev, "%s: Fill the ring buffer with new
> bitstream
> > data", __func__);
> > -
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> >  	ret = fill_ringbuffer(inst);
> >  	if (ret) {
> >  		dev_warn(inst->dev->dev, "Filling ring buffer failed\n"); @@
> > -1709,6 +1717,8 @@ static void wave5_vpu_dec_device_run(void *priv)
> >
> >  finish_job_and_return:
> >  	dev_dbg(inst->dev->dev, "%s: leave and finish job", __func__);
> > +	pm_runtime_mark_last_busy(inst->dev->dev);
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  	v4l2_m2m_job_finish(inst->v4l2_m2m_dev, m2m_ctx);  }
> >
> > @@ -1866,7 +1876,6 @@ static int wave5_vpu_open_dec(struct file *filp)
> >  	}
> >
> >  	wave5_vdi_allocate_sram(inst->dev);
> > -
> >  	return 0;
> >
> >  cleanup_inst:
> > diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu-enc.c
> > b/drivers/media/platform/chips-media/wave5/wave5-vpu-enc.c
> > index f04baa93a..14fd26204 100644
> > --- a/drivers/media/platform/chips-media/wave5/wave5-vpu-enc.c
> > +++ b/drivers/media/platform/chips-media/wave5/wave5-vpu-enc.c
> > @@ -5,6 +5,7 @@
> >   * Copyright (C) 2021-2023 CHIPS&MEDIA INC
> >   */
> >
> > +#include <linux/pm_runtime.h>
> >  #include "wave5-helper.h"
> >
> >  #define VPU_ENC_DEV_NAME "C&M Wave5 VPU encoder"
> > @@ -1310,6 +1311,7 @@ static int wave5_vpu_enc_start_streaming(struct
> vb2_queue *q, unsigned int count
> >  	struct v4l2_m2m_ctx *m2m_ctx = inst->v4l2_fh.m2m_ctx;
> >  	int ret = 0;
> >
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> >  	v4l2_m2m_update_start_streaming_state(m2m_ctx, q);
> >
> >  	if (inst->state == VPU_INST_STATE_NONE && q->type ==
> > V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) { @@ -1364,9 +1366,13 @@ static int
> wave5_vpu_enc_start_streaming(struct vb2_queue *q, unsigned int count
> >  	if (ret)
> >  		goto return_buffers;
> >
> > +	pm_runtime_mark_last_busy(inst->dev->dev);
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  	return 0;
> >  return_buffers:
> >  	wave5_return_bufs(q, VB2_BUF_STATE_QUEUED);
> > +	pm_runtime_mark_last_busy(inst->dev->dev);
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  	return ret;
> >  }
> >
> > @@ -1408,6 +1414,7 @@ static void wave5_vpu_enc_stop_streaming(struct
> vb2_queue *q)
> >  	 */
> >
> >  	dev_dbg(inst->dev->dev, "%s: type: %u\n", __func__, q->type);
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> >
> >  	if (wave5_vpu_both_queues_are_streaming(inst))
> >  		switch_state(inst, VPU_INST_STATE_STOP); @@ -1432,6 +1439,9
> @@
> > static void wave5_vpu_enc_stop_streaming(struct vb2_queue *q)
> >  		streamoff_output(inst, q);
> >  	else
> >  		streamoff_capture(inst, q);
> > +
> > +	pm_runtime_mark_last_busy(inst->dev->dev);
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  }
> >
> >  static const struct vb2_ops wave5_vpu_enc_vb2_ops = { @@ -1478,6
> > +1488,7 @@ static void wave5_vpu_enc_device_run(void *priv)
> >  	u32 fail_res = 0;
> >  	int ret = 0;
> >
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> >  	switch (inst->state) {
> >  	case VPU_INST_STATE_PIC_RUN:
> >  		ret = start_encode(inst, &fail_res); @@ -1491,6 +1502,8 @@
> static
> > void wave5_vpu_enc_device_run(void *priv)
> >  			break;
> >  		}
> >  		dev_dbg(inst->dev->dev, "%s: leave with active job",
> __func__);
> > +		pm_runtime_mark_last_busy(inst->dev->dev);
> > +		pm_runtime_put_autosuspend(inst->dev->dev);
> >  		return;
> >  	default:
> >  		WARN(1, "Execution of a job in state %s is invalid.\n", @@ -
> 1498,6
> > +1511,8 @@ static void wave5_vpu_enc_device_run(void *priv)
> >  		break;
> >  	}
> >  	dev_dbg(inst->dev->dev, "%s: leave and finish job", __func__);
> > +	pm_runtime_mark_last_busy(inst->dev->dev);
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  	v4l2_m2m_job_finish(inst->v4l2_m2m_dev, m2m_ctx);  }
> >
> > @@ -1735,7 +1750,6 @@ static int wave5_vpu_open_enc(struct file *filp)
> >  	}
> >
> >  	wave5_vdi_allocate_sram(inst->dev);
> > -
> >  	return 0;
> >
> >  cleanup_inst:
> > diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > index 2323dba75..6b4794e0e 100644
> > --- a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > +++ b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > @@ -10,6 +10,7 @@
> >  #include <linux/clk.h>
> >  #include <linux/firmware.h>
> >  #include <linux/interrupt.h>
> > +#include <linux/pm_runtime.h>
> >  #include "wave5-vpu.h"
> >  #include "wave5-regdefine.h"
> >  #include "wave5-vpuconfig.h"
> > @@ -117,6 +118,38 @@ static int wave5_vpu_load_firmware(struct device
> *dev, const char *fw_name,
> >  	return 0;
> >  }
> >
> > +static int wave5_pm_suspend(struct device *dev) {
> > +	struct vpu_device *vpu = dev_get_drvdata(dev);
> > +
> > +	if (pm_runtime_suspended(dev))
> > +		return 0;
> > +
> > +	wave5_vpu_sleep_wake(dev, true, NULL, 0);
> > +	clk_bulk_disable_unprepare(vpu->num_clks, vpu->clks);
> > +
> > +	return 0;
> > +}
> > +
> > +static int wave5_pm_resume(struct device *dev) {
> > +	struct vpu_device *vpu = dev_get_drvdata(dev);
> > +	int ret = 0;
> > +
> > +	wave5_vpu_sleep_wake(dev, false, NULL, 0);
> > +	ret = clk_bulk_prepare_enable(vpu->num_clks, vpu->clks);
> > +	if (ret) {
> > +		dev_err(dev, "Enabling clocks, fail: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static const struct dev_pm_ops wave5_pm_ops = {
> > +	SET_RUNTIME_PM_OPS(wave5_pm_suspend, wave5_pm_resume, NULL) };
> > +
> >  static int wave5_vpu_probe(struct platform_device *pdev)  {
> >  	int ret;
> > @@ -233,6 +266,12 @@ static int wave5_vpu_probe(struct platform_device
> *pdev)
> >  		 (match_data->flags & WAVE5_IS_DEC) ? "'DECODE'" : "");
> >  	dev_info(&pdev->dev, "Product Code:      0x%x\n", dev->product_code);
> >  	dev_info(&pdev->dev, "Firmware Revision: %u\n", fw_revision);
> > +
> > +	pm_runtime_set_autosuspend_delay(&pdev->dev, 5000);
> > +	pm_runtime_use_autosuspend(&pdev->dev);
> > +	pm_runtime_enable(&pdev->dev);
> > +	wave5_vpu_sleep_wake(&pdev->dev, true, NULL, 0);
> > +
> >  	return 0;
> >
> >  err_enc_unreg:
> > @@ -255,6 +294,9 @@ static int wave5_vpu_remove(struct platform_device
> > *pdev)  {
> >  	struct vpu_device *dev = dev_get_drvdata(&pdev->dev);
> >
> > +	pm_runtime_put_sync(&pdev->dev);
> > +	pm_runtime_disable(&pdev->dev);
> > +
> >  	mutex_destroy(&dev->dev_lock);
> >  	mutex_destroy(&dev->hw_lock);
> >  	clk_bulk_disable_unprepare(dev->num_clks, dev->clks); @@ -282,6
> > +324,7 @@ static struct platform_driver wave5_vpu_driver = {
> >  	.driver = {
> >  		.name = VPU_PLATFORM_DEVICE_NAME,
> >  		.of_match_table = of_match_ptr(wave5_dt_ids),
> > +		.pm = &wave5_pm_ops,
> >  		},
> >  	.probe = wave5_vpu_probe,
> >  	.remove = wave5_vpu_remove,
> > diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpuapi.c
> > b/drivers/media/platform/chips-media/wave5/wave5-vpuapi.c
> > index 86b399372..b2357d1b5 100644
> > --- a/drivers/media/platform/chips-media/wave5/wave5-vpuapi.c
> > +++ b/drivers/media/platform/chips-media/wave5/wave5-vpuapi.c
> > @@ -6,6 +6,8 @@
> >   */
> >
> >  #include <linux/bug.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/delay.h>
> >  #include "wave5-vpuapi.h"
> >  #include "wave5-regdefine.h"
> >  #include "wave5.h"
> > @@ -200,6 +202,8 @@ int wave5_vpu_dec_close(struct vpu_instance *inst,
> u32 *fail_res)
> >  	if (!inst->codec_info)
> >  		return -EINVAL;
> >
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> > +
> >  	ret = mutex_lock_interruptible(&vpu_dev->hw_lock);
> >  	if (ret)
> >  		return ret;
> > @@ -234,7 +238,7 @@ int wave5_vpu_dec_close(struct vpu_instance *inst,
> > u32 *fail_res)
> >
> >  unlock_and_return:
> >  	mutex_unlock(&vpu_dev->hw_lock);
> > -
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> >  	return ret;
> >  }
> >
> > @@ -702,6 +706,8 @@ int wave5_vpu_enc_close(struct vpu_instance *inst,
> u32 *fail_res)
> >  	if (!inst->codec_info)
> >  		return -EINVAL;
> >
> > +	pm_runtime_resume_and_get(inst->dev->dev);
> > +
> >  	ret = mutex_lock_interruptible(&vpu_dev->hw_lock);
> >  	if (ret)
> >  		return ret;
> > @@ -733,9 +739,10 @@ int wave5_vpu_enc_close(struct vpu_instance *inst,
> u32 *fail_res)
> >  	}
> >
> >  	wave5_vdi_free_dma_memory(vpu_dev, &p_enc_info->vb_task);
> > -
> >  	mutex_unlock(&vpu_dev->hw_lock);
> >
> > +	pm_runtime_put_autosuspend(inst->dev->dev);
> > +
> >  	return 0;
> >  }
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > >
> > > >
> > > > Thanks.
> > > > Jackson
> > > >
> > > > >
> > > > > The delay means a timer, so there is no input for 5 secs, then
> > > > > timeout callback is called, And suspend is set, if new activity
> > > > > comes, the device is resumed again ?
> > > > > My understanding is correct ?
> > > > >
> > > >
> > > >
> > > > >
> > > > >
> > > > > > Nicolas
> > > > > >
> > > > > > >
> > > > > > > Thanks.
> > > > > > >
> > > > > > >
> > > > > > > > There is of course other places where you'll have to make
> > > > > > > > sure the hardware is resumed, like on close, as you want
> > > > > > > > to remove the
> > > > > instance.
> > > > > > > > There is also small queries here and there that need to be
> > > > > > > > surrounded with resume/put, but with the redesign, most of
> > > > > > > > the HW access now take place inside device_run() only.
> > > > > > > >
> > > > > > > > Open/Close is not invalid, but it has a lot of issues, as
> > > > > > > > any random application can endup disabling the kernel
> > > > > > > > ability to save
> > > > > power.
> > > > > > > > Personally, I think we should at least give it a try, and
> > > > > > > > document valid reason not to do so if we find hardware
> issues.
> > > > > > > > Otherwise, this sounds like all we care is ticking the box
> > > > > > > > "this driver has runtime PM" without actually caring about
> > > effective power saving.
> > > > > > > >
> > > > > > > > Nicolas
> > > > > > > >
> > > > > > > > >
> > > > > > > > > Thanks.
> > > > > > > > >
> > > > > > > > > > Le lundi 19 février 2024 à 04:04 +0000, jackson.lee a
> écrit :
> > > > > > > > > > > Hi Nicolas
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > > This seems very unnatural. We do the get() in
> > > > > > > > > > > > "start_streaming()", but the
> > > > > > > > > > > > put() is only done when the device is closed, or
> > > > > > > > > > > > when the driver is removed. As this is not
> > > > > > > > > > > > balanced, you seem to have to check the suspended
> > > > > > > > > > > > condition all over
> > > the place.
> > > > > > > > > > > >
> > > > > > > > > > > > I think we could aim for
> > > > > > > > > > > > start_streaming()/stop_streaming()
> > > > > > > > > > > > for your get/put placement. At least they will be
> > > > > > > > > > > > bound to an entirely balanced
> > > > > > > > > > API.
> > > > > > > > > > > > But then, a media player in paused sate will
> > > > > > > > > > > > prevent that device from being suspended.
> > > > > > > > > > > >
> > > > > > > > > > > > If the HW is capable of preserving enough state,
> > > > > > > > > > > > and From the short doc I have it gives me the
> > > > > > > > > > > > impression it can preserve that, I'd suggest to
> > > > > > > > > > > > follow what hantro driver is doing. What is does
> > > > > > > > > > > > is that it will do get() in device_run(), and
> > > > > > > > > > > > put() whenever the job completes. This driver has
> > > > > > > > > > > > been designed so when there is no job, it means
> > > > > > > > > > > > the firmware is currently idle and
> > > looking for more work.
> > > > > > > > > > > > So it seems like the perfect moment to
> > > > > > > > do suspend it.
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > Thanks your comment,
> > > > > > > > > > >
> > > > > > > > > > > Currently they are not balanced, If we puts "the put
> > > functon"
> > > > > > > > > > > into the stop_streaming, our hw is stalled
> > > > > > > > > > until doing wake-up command, so our v4l2 device become
> block.
> > > > > > > > > > > so I'd like to update the below instead of calling
> > > > > > > > > > > get at the
> > > > > > > > > > start_streaming function.
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > @@ -1867,6 +1868,13 @@ static int
> > > > > > > > > > > wave5_vpu_open_dec(struct file
> > > > > > > > > > > *filp)
> > > > > > > > > > >
> > > > > > > > > > >         wave5_vdi_allocate_sram(inst->dev);
> > > > > > > > > > >
> > > > > > > > > > > +       err = pm_runtime_resume_and_get(inst->dev->dev);
> > > > > > > > > > > +       if (err) {
> > > > > > > > > > > +               dev_err(inst->dev->dev, "decoder
> > > > > > > > > > > + runtime resume
> > > > > > > > > > failed %d\n", err);
> > > > > > > > > > > +               ret = -EINVAL;
> > > > > > > > > > > +               goto cleanup_inst;
> > > > > > > > > > > +       }
> > > > > > > > > > > +
> > > > > > > > > > >         return 0;
> > > > > > > > > >
> > > > > > > > > > I guess we need to discuss the power management
> > > > > > > > > > strategy for this
> > > > > > > > device.
> > > > > > > > > > If you do resume_and_get() in open(), and then put in
> > > > > > > > > > close(), that seems balanced. But in term of power
> > > > > > > > > > saving, it might not be very strong. If you have a
> > > > > > > > > > media player that is set to pause and then placed in
> > > > > > > > > > the background, you still keep the IP running. This is
> > > > > > > > > > extremely common, since application cannot close their
> > > > > > > > > > device without loosing the reference frames, and thus
> > > > > > > > > > having to do extra work on resume to seek back to the
> > > > > > > > > > previous sync point and drop
> > > > > > > > unneeded frames.
> > > > > > > > > >
> > > > > > > > > > It seems like the whole point of asking the firmware
> > > > > > > > > > to save the state and suspend is to be able to do so
> > > > > > > > > > while there is meaningful sate in the firt place.
> > > > > > > > > > If we are to suspend only when there is no meaningful
> > > > > > > > > > state, we could just free all resources and power it
> > > > > > > > > > off
> > > completely.
> > > > > > > > > > (This is just for illustration, its probably to slow
> > > > > > > > > > to boot the firmware at
> > > > > > > > > > runtime)
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > I understand you suffered lockup with a
> > > > > > > > > > start_streaming() for resume_and_get(), and
> > > > > > > > > > stop_streaming() for put(), this may simply indicate
> > > > > > > > > > that some hardware access are needed between these
> > > > > > > > > > two. Can you write down a power management plan that
> > > > > > > > > > would effectively save power in common use cases ? We
> > > > > > > > > > can certainly help in refactoring the
> > > > > > > > code to make that happen.
> > > > > > > > > >
> > > > > > > > > > Nicolas
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > > Le mercredi 31 janvier 2024 à 10:30 +0900,
> > > > > > > > > > > > jackson.lee a
> > > > > > écrit :
> > > > > > > > > > > > > There are two device run-time PM callbacks
> > > > > > > > > > > > > defined in 'struct
> > > > > > > > > > > > dev_pm_ops'
> > > > > > > > > > > > > int (*runtime_suspend)(struct device *dev); int
> > > > > > > > > > > > > (*runtime_resume)(struct device *dev);
> > > > > > > > > > > >
> > > > > > > > > > > > I wonder how useful is it to teach everyone what
> > > > > > > > > > > > the generic 'struct dev_pm_ops'
> > > > > > > > > > > > contains. Perhaps you simply wanted that this
> > > > > > > > > > > > patch implement both suspend and resume ops ?
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > Signed-off-by: Jackson Lee
> > > > > > > > > > > > > <jackson.lee@chipsnmedia.com>
> > > > > > > > > > > > > Signed-off-by: Nas Chung
> > > > > > > > > > > > > <nas.chung@chipsnmedia.com>
> > > > > > > > > > > > > ---
> > > > > > > > > > > > >  .../platform/chips-media/wave5/wave5-hw.c     |  5
> +-
> > > > > > > > > > > > >  .../chips-media/wave5/wave5-vpu-dec.c         |  9
> +++
> > > > > > > > > > > > >  .../chips-media/wave5/wave5-vpu-enc.c         |  9
> +++
> > > > > > > > > > > > >  .../platform/chips-media/wave5/wave5-vpu.c    | 68
> > > > > > > > > > +++++++++++++++++++
> > > > > > > > > > > > >  .../platform/chips-media/wave5/wave5-vpuapi.c |
> > > > > > > > > > > > > 7
> > > > > > > > > > > > > ++ .../media/platform/chips-media/wave5/wave5.h
> > > > > > > > > > > > > ++ |
> > > > > > > > > > > > > 3 +
> > > > > > > > > > > > >  6 files changed, 99 insertions(+), 2
> > > > > > > > > > > > > deletions(-)
> > > > > > > > > > > > >
> > > > > > > > > > > > > diff --git
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5-
> hw.
> > > > > > > > > > > > > c
> > > > > > > > > > > > > b/drivers/media/platform/chips-media/wave5/wave5-
> hw.
> > > > > > > > > > > > > c index 8ad7f3a28ae1..8aade5a38439 100644
> > > > > > > > > > > > > ---
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5-
> hw.
> > > > > > > > > > > > > c
> > > > > > > > > > > > > +++ b/drivers/media/platform/chips-media/wave5/w
> > > > > > > > > > > > > +++ ave5-
> > > hw.
> > > > > > > > > > > > > +++ c
> > > > > > > > > > > > > @@ -503,6 +503,7 @@ int
> > > > > > > > > > > > > wave5_vpu_build_up_dec_param(struct
> > > > > > > > > > > > > vpu_instance
> > > > > > > > > > > > *inst,
> > > > > > > > > > > > >  	/* This register must be reset explicitly */
> > > > > > > > > > > > >  	vpu_write_reg(inst->dev, W5_CMD_EXT_ADDR, 0);
> > > > > > > > > > > > >  	vpu_write_reg(inst->dev,
> > > > > > > > > > > > > W5_CMD_NUM_CQ_DEPTH_M1, (COMMAND_QUEUE_DEPTH -
> > > > > > > > > > > > > 1));
> > > > > > > > > > > > > +	vpu_write_reg(inst->dev, W5_CMD_ERR_CONCEAL,
> > > > > > > > > > > > > +0);
> > > > > > > > > > > >
> > > > > > > > > > > > In some way, the relation between suspend and this
> > > > > > > > > > > > register write is not obvious. If its not related,
> > > > > > > > > > > > please do this in its
> > > > > > > > own patch.
> > > > > > > > > > > > Otherwise you want to explain why you needed this
> > > > > > > > > > > > (possibly just in the commit message).
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > >  	ret = send_firmware_command(inst,
> > > > > > > > > > > > > W5_CREATE_INSTANCE, true, NULL,
> > > > > > > > > > > > NULL);
> > > > > > > > > > > > >  	if (ret) {
> > > > > > > > > > > > > @@ -1075,8 +1076,8 @@ int
> > > > > > > > > > > > > wave5_vpu_re_init(struct device *dev, u8 *fw,
> > > > > > > > > > > > size_t size)
> > > > > > > > > > > > >  	return setup_wave5_properties(dev);  }
> > > > > > > > > > > > >
> > > > > > > > > > > > > -static int wave5_vpu_sleep_wake(struct device
> > > > > > > > > > > > > *dev, bool i_sleep_wake,
> > > > > > > > > > > > const uint16_t *code,
> > > > > > > > > > > > > -				size_t size)
> > > > > > > > > > > > > +int wave5_vpu_sleep_wake(struct device *dev,
> > > > > > > > > > > > > +bool i_sleep_wake, const
> > > > > > > > > > > > uint16_t *code,
> > > > > > > > > > > > > +			 size_t size)
> > > > > > > > > > > > >  {
> > > > > > > > > > > > >  	u32 reg_val;
> > > > > > > > > > > > >  	struct vpu_buf *common_vb; diff --git
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu
> > > > > > > > > > > > > -dec
> > > > > > > > > > > > > .c
> > > > > > > > > > > > > b/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu -dec .c index ef227af72348..328a7a8f26c5
> > > > > > > > > > > > > 100644
> > > > > > > > > > > > > ---
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu
> > > > > > > > > > > > > -dec
> > > > > > > > > > > > > .c
> > > > > > > > > > > > > +++ b/drivers/media/platform/chips-media/wave5/w
> > > > > > > > > > > > > +++ ave5
> > > > > > > > > > > > > +++ -vpu
> > > > > > > > > > > > > +++ -d
> > > > > > > > > > > > > +++ ec.c
> > > > > > > > > > > > > @@ -5,6 +5,7 @@
> > > > > > > > > > > > >   * Copyright (C) 2021-2023 CHIPS&MEDIA INC
> > > > > > > > > > > > >   */
> > > > > > > > > > > > >
> > > > > > > > > > > > > +#include <linux/pm_runtime.h>
> > > > > > > > > > > > >  #include "wave5-helper.h"
> > > > > > > > > > > > >
> > > > > > > > > > > > >  #define VPU_DEC_DEV_NAME "C&M Wave5 VPU decoder"
> > > > > > > > > > > > > @@ -1387,9 +1388,17 @@ static int
> > > > > > > > > > > > > wave5_vpu_dec_start_streaming(struct
> > > > > > > > > > > > > vb2_queue *q, unsigned int count
> > > > > > > > > > > > >
> > > > > > > > > > > > >  	if (q->type ==
> > > V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE
> > > > > > > > > > > > > &&
> > > > > > > > > > > > > inst-
> > > > > > > > > > > state
> > > > > > > > > > > > > ==
> > > > > > > > > > > > VPU_INST_STATE_NONE) {
> > > > > > > > > > > > >  		struct dec_open_param open_param;
> > > > > > > > > > > > > +		int err = 0;
> > > > > > > > > > > > >
> > > > > > > > > > > > >  		memset(&open_param, 0, sizeof(struct
> > > > > > dec_open_param));
> > > > > > > > > > > > >
> > > > > > > > > > > > > +		err = pm_runtime_resume_and_get(inst-
> > > > dev->dev);
> > > > > > > > > > > > > +		if (err) {
> > > > > > > > > > > > > +			dev_err(inst->dev->dev, "decoder
> > > runtime
> > > > > > resume
> > > > > > > > > > > > failed %d\n", err);
> > > > > > > > > > > > > +			ret = -EINVAL;
> > > > > > > > > > > > > +			goto return_buffers;
> > > > > > > > > > > > > +		}
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  		ret =
> > > wave5_vpu_dec_allocate_ring_buffer(inst);
> > > > > > > > > > > > >  		if (ret)
> > > > > > > > > > > > >  			goto return_buffers; diff --git
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu
> > > > > > > > > > > > > -enc
> > > > > > > > > > > > > .c
> > > > > > > > > > > > > b/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu -enc .c index 761775216cd4..ff73d69de41c
> > > > > > > > > > > > > 100644
> > > > > > > > > > > > > ---
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu
> > > > > > > > > > > > > -enc
> > > > > > > > > > > > > .c
> > > > > > > > > > > > > +++ b/drivers/media/platform/chips-media/wave5/w
> > > > > > > > > > > > > +++ ave5
> > > > > > > > > > > > > +++ -vpu
> > > > > > > > > > > > > +++ -e
> > > > > > > > > > > > > +++ nc.c
> > > > > > > > > > > > > @@ -5,6 +5,7 @@
> > > > > > > > > > > > >   * Copyright (C) 2021-2023 CHIPS&MEDIA INC
> > > > > > > > > > > > >   */
> > > > > > > > > > > > >
> > > > > > > > > > > > > +#include <linux/pm_runtime.h>
> > > > > > > > > > > > >  #include "wave5-helper.h"
> > > > > > > > > > > > >
> > > > > > > > > > > > >  #define VPU_ENC_DEV_NAME "C&M Wave5 VPU encoder"
> > > > > > > > > > > > > @@ -1387,9 +1388,17 @@ static int
> > > > > > > > > > > > > wave5_vpu_enc_start_streaming(struct
> > > > > > > > > > > > > vb2_queue *q, unsigned int count
> > > > > > > > > > > > >
> > > > > > > > > > > > >  	if (inst->state == VPU_INST_STATE_NONE && q-
> > > > type
> > > > > > > > > > > > > ==
> > > > > > > > > > > > V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
> > > > > > > > > > > > >  		struct enc_open_param open_param;
> > > > > > > > > > > > > +		int err = 0;
> > > > > > > > > > > > >
> > > > > > > > > > > > >  		memset(&open_param, 0, sizeof(struct
> > > > > > enc_open_param));
> > > > > > > > > > > > >
> > > > > > > > > > > > > +		err = pm_runtime_resume_and_get(inst-
> > > > dev->dev);
> > > > > > > > > > > > > +		if (err) {
> > > > > > > > > > > > > +			dev_err(inst->dev->dev, "encoder
> > > runtime
> > > > > > resume
> > > > > > > > > > > > failed %d\n", err);
> > > > > > > > > > > > > +			ret = -EINVAL;
> > > > > > > > > > > > > +			goto return_buffers;
> > > > > > > > > > > > > +		}
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  		wave5_set_enc_openparam(&open_param,
> > > inst);
> > > > > > > > > > > > >
> > > > > > > > > > > > >  		ret = wave5_vpu_enc_open(inst,
> > > &open_param);
> > > > > > diff --
> > > > > > > > > > git
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu
> > > > > > > > > > > > > .c
> > > > > > > > > > > > > b/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu .c index 0d90b5820bef..f81409740a56 100644
> > > > > > > > > > > > > ---
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -vpu
> > > > > > > > > > > > > .c
> > > > > > > > > > > > > +++ b/drivers/media/platform/chips-media/wave5/w
> > > > > > > > > > > > > +++ ave5
> > > > > > > > > > > > > +++ -vpu
> > > > > > > > > > > > > +++ .c
> > > > > > > > > > > > > @@ -10,6 +10,7 @@
> > > > > > > > > > > > >  #include <linux/clk.h>
> > > > > > > > > > > > >  #include <linux/firmware.h>  #include
> > > > > > > > > > > > > <linux/interrupt.h>
> > > > > > > > > > > > > +#include <linux/pm_runtime.h>
> > > > > > > > > > > > >  #include "wave5-vpu.h"
> > > > > > > > > > > > >  #include "wave5-regdefine.h"
> > > > > > > > > > > > >  #include "wave5-vpuconfig.h"
> > > > > > > > > > > > > @@ -117,6 +118,65 @@ static int
> > > > > > > > > > > > > wave5_vpu_load_firmware(struct device
> > > > > > > > > > > > *dev, const char *fw_name,
> > > > > > > > > > > > >  	return 0;
> > > > > > > > > > > > >  }
> > > > > > > > > > > > >
> > > > > > > > > > > > > +static __maybe_unused int
> > > > > > > > > > > > > +wave5_pm_suspend(struct device
> > > > > > > > > > > > > +*dev)
> > > > > > > > {
> > > > > > > > > > > > > +	struct vpu_device *vpu = dev_get_drvdata(dev);
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	if (pm_runtime_suspended(dev))
> > > > > > > > > > > > > +		return 0;
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	wave5_vpu_sleep_wake(dev, true, NULL, 0);
> > > > > > > > > > > > > +	clk_bulk_disable_unprepare(vpu->num_clks,
> > > > > > > > > > > > > +vpu->clks);
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	return 0;
> > > > > > > > > > > > > +}
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +static __maybe_unused int
> > > > > > > > > > > > > +wave5_pm_resume(struct device
> > > > > > *dev) {
> > > > > > > > > > > > > +	struct vpu_device *vpu = dev_get_drvdata(dev);
> > > > > > > > > > > > > +	int ret = 0;
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	wave5_vpu_sleep_wake(dev, false, NULL, 0);
> > > > > > > > > > > > > +	ret = clk_bulk_prepare_enable(vpu->num_clks,
> > > vpu-
> > > > > > > clks);
> > > > > > > > > > > > > +	if (ret) {
> > > > > > > > > > > > > +		dev_err(dev, "Enabling clocks,
> > > fail: %d\n",
> > > > > > ret);
> > > > > > > > > > > > > +		return ret;
> > > > > > > > > > > > > +	}
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	return ret;
> > > > > > > > > > > > > +}
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +static __maybe_unused int wave5_suspend(struct
> > > > > > > > > > > > > +device
> > > > > > > > > > > > > +*dev)
> > > > > > {
> > > > > > > > > > > > > +	struct vpu_device *vpu = dev_get_drvdata(dev);
> > > > > > > > > > > > > +	struct vpu_instance *inst;
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	list_for_each_entry(inst, &vpu->instances, list)
> > > > > > > > > > > > > +		v4l2_m2m_suspend(inst->v4l2_m2m_dev);
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	return pm_runtime_force_suspend(dev); }
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +static __maybe_unused int wave5_resume(struct
> > > > > > > > > > > > > +device
> > > > > > > > > > > > > +*dev)
> > > > > > {
> > > > > > > > > > > > > +	struct vpu_device *vpu = dev_get_drvdata(dev);
> > > > > > > > > > > > > +	struct vpu_instance *inst;
> > > > > > > > > > > > > +	int ret = 0;
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	ret = pm_runtime_force_resume(dev);
> > > > > > > > > > > > > +	if (ret < 0)
> > > > > > > > > > > > > +		return ret;
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	list_for_each_entry(inst, &vpu->instances, list)
> > > > > > > > > > > > > +		v4l2_m2m_resume(inst->v4l2_m2m_dev);
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	return ret;
> > > > > > > > > > > > > +}
> > > > > > > > > > > >
> > > > > > > > > > > > The functions wave5_suspend() and wave5_resume()
> > > > > > > > > > > > are not just "maybe_unsued" but actually never
> > > > > > > > > > > > used. What was the
> > > > > > intention ?
> > > > > > > > > > > > Considering the usage of __maybe_unused has been
> > > > > > > > > > > > such a bad friend for this one, could you instead
> > > > > > > > > > > > bracket the functions with an
> > > > > > > > > > explicit ?
> > > > > > > > > > > >
> > > > > > > > > > > > #ifdef CONFIG_PM
> > > > > > > > > > > > #endif
> > > > > > > > > > > >
> > > > > > > > > > > > This way the compiler will have a word if you
> > > > > > > > > > > > implement something that you forgot to actually use.
> > > > > > > > > > > >
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +static const struct dev_pm_ops wave5_pm_ops = {
> > > > > > > > > > > > > +	SET_RUNTIME_PM_OPS(wave5_pm_suspend,
> > > > > > > > > > > > > +wave5_pm_resume,
> > > > > > > > > > NULL) };
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  static int wave5_vpu_probe(struct
> > > > > > > > > > > > > platform_device
> > > > > > > > > > > > > *pdev)
> > > > > {
> > > > > > > > > > > > >  	int ret;
> > > > > > > > > > > > > @@ -232,6 +292,10 @@ static int
> > > > > > > > > > > > > wave5_vpu_probe(struct platform_device
> > > > > > > > > > > > *pdev)
> > > > > > > > > > > > >  		 (match_data->flags & WAVE5_IS_DEC) ?
> > > > > > "'DECODE'" : "");
> > > > > > > > > > > > >  	dev_info(&pdev->dev, "Product Code:      0x%x\n",
> > > dev-
> > > > > > > > > > > product_code);
> > > > > > > > > > > > >  	dev_info(&pdev->dev, "Firmware Revision:
> > > > > > > > > > > > > %u\n", fw_revision);
> > > > > > > > > > > > > +
> > > > > > > > > > > > > +	pm_runtime_enable(&pdev->dev);
> > > > > > > > > > > > > +	wave5_vpu_sleep_wake(&pdev->dev, true, NULL,
> > > > > > > > > > > > > +0);
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  	return 0;
> > > > > > > > > > > > >
> > > > > > > > > > > > >  err_enc_unreg:
> > > > > > > > > > > > > @@ -254,6 +318,9 @@ static int
> > > > > > > > > > > > > wave5_vpu_remove(struct platform_device
> > > > > > > > > > > > > *pdev)  {
> > > > > > > > > > > > >  	struct vpu_device *dev =
> > > > > > > > > > > > > dev_get_drvdata(&pdev->dev);
> > > > > > > > > > > > >
> > > > > > > > > > > > > +	pm_runtime_put_sync(&pdev->dev);
> > > > > > > > > > > > > +	pm_runtime_disable(&pdev->dev);
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  	mutex_destroy(&dev->dev_lock);
> > > > > > > > > > > > >  	mutex_destroy(&dev->hw_lock);
> > > > > > > > > > > > >  	clk_bulk_disable_unprepare(dev->num_clks,
> > > > > > > > > > > > > dev->clks);
> > > > > > @@
> > > > > > > > > > > > > -
> > > > > > > > > > 281,6
> > > > > > > > > > > > > +348,7 @@ static struct platform_driver
> > > > > > > > > > > > > +wave5_vpu_driver = {
> > > > > > > > > > > > >  	.driver = {
> > > > > > > > > > > > >  		.name = VPU_PLATFORM_DEVICE_NAME,
> > > > > > > > > > > > >  		.of_match_table =
> > > of_match_ptr(wave5_dt_ids),
> > > > > > > > > > > > > +		.pm = &wave5_pm_ops,
> > > > > > > > > > > > >  		},
> > > > > > > > > > > > >  	.probe = wave5_vpu_probe,
> > > > > > > > > > > > >  	.remove = wave5_vpu_remove, diff --git
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -
> > > vpuapi.
> > > > > > > > > > > > > c
> > > > > > > > > > > > > b/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -
> > > vpuapi.
> > > > > > > > > > > > > c index 1a3efb638dde..f1f8e4fc8474 100644
> > > > > > > > > > > > > ---
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > -
> > > vpuapi.
> > > > > > > > > > > > > c
> > > > > > > > > > > > > +++ b/drivers/media/platform/chips-media/wave5/w
> > > > > > > > > > > > > +++ ave5
> > > > > > > > > > > > > +++ -vpu
> > > > > > > > > > > > > +++ ap
> > > > > > > > > > > > > +++ i.c
> > > > > > > > > > > > > @@ -6,6 +6,7 @@
> > > > > > > > > > > > >   */
> > > > > > > > > > > > >
> > > > > > > > > > > > >  #include <linux/bug.h>
> > > > > > > > > > > > > +#include <linux/pm_runtime.h>
> > > > > > > > > > > > >  #include "wave5-vpuapi.h"
> > > > > > > > > > > > >  #include "wave5-regdefine.h"
> > > > > > > > > > > > >  #include "wave5.h"
> > > > > > > > > > > > > @@ -232,6 +233,9 @@ int
> > > > > > > > > > > > > wave5_vpu_dec_close(struct vpu_instance *inst,
> > > > > > > > > > > > > u32 *fail_res)
> > > > > > > > > > > > >
> > > > > > > > > > > > >  	wave5_vdi_free_dma_memory(vpu_dev,
> > > > > > > > > > > > > &p_dec_info->vb_task);
> > > > > > > > > > > > >
> > > > > > > > > > > > > +	if (!pm_runtime_suspended(inst->dev->dev))
> > > > > > > > > > > > > +		pm_runtime_put_sync(inst->dev->dev);
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  unlock_and_return:
> > > > > > > > > > > > >  	mutex_unlock(&vpu_dev->hw_lock);
> > > > > > > > > > > > >
> > > > > > > > > > > > > @@ -734,6 +738,9 @@ int
> > > > > > > > > > > > > wave5_vpu_enc_close(struct vpu_instance *inst,
> > > > > > > > > > > > > u32 *fail_res)
> > > > > > > > > > > > >
> > > > > > > > > > > > >  	wave5_vdi_free_dma_memory(vpu_dev,
> > > > > > > > > > > > > &p_enc_info->vb_task);
> > > > > > > > > > > > >
> > > > > > > > > > > > > +	if (!pm_runtime_suspended(inst->dev->dev))
> > > > > > > > > > > > > +		pm_runtime_put_sync(inst->dev->dev);
> > > > > > > > > > > >
> > > > > > > > > > > > This seems very unnatural. We do the get() in
> > > > > > > > > > > > "start_streaming()", but the
> > > > > > > > > > > > put() is only done when the device is closed, or
> > > > > > > > > > > > when the driver is removed. As this is not
> > > > > > > > > > > > balanced, you seem to have to check the suspended
> > > > > > > > > > > > condition all over
> > > the place.
> > > > > > > > > > > >
> > > > > > > > > > > > I think we could aim for
> > > > > > > > > > > > start_streaming()/stop_streaming()
> > > > > > > > > > > > for your get/put placement. At least they will be
> > > > > > > > > > > > bound to an entirely balanced
> > > > > > > > > > API.
> > > > > > > > > > > > But then, a media player in paused sate will
> > > > > > > > > > > > prevent that device from being suspended.
> > > > > > > > > > > >
> > > > > > > > > > > > If the HW is capable of preserving enough state,
> > > > > > > > > > > > and From the short doc I have it gives me the
> > > > > > > > > > > > impression it can preserve that, I'd suggest to
> > > > > > > > > > > > follow what hantro driver is doing. What is does
> > > > > > > > > > > > is that it will do get() in device_run(), and
> > > > > > > > > > > > put() whenever the job completes. This driver has
> > > > > > > > > > > > been designed so when there is no job, it means
> > > > > > > > > > > > the firmware is currently idle and
> > > looking for more work.
> > > > > > > > > > > > So it seems like the perfect moment to
> > > > > > > > do suspend it.
> > > > > > > > > > > >
> > > > > > > > > > > > Nicolas
> > > > > > > > > > > >
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  	mutex_unlock(&vpu_dev->hw_lock);
> > > > > > > > > > > > >
> > > > > > > > > > > > >  	return 0;
> > > > > > > > > > > > > diff --git
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > .h
> > > > > > > > > > > > > b/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > .h index 063028eccd3b..6125eff938a8 100644
> > > > > > > > > > > > > ---
> > > > > > > > > > > > > a/drivers/media/platform/chips-media/wave5/wave5
> > > > > > > > > > > > > .h
> > > > > > > > > > > > > +++ b/drivers/media/platform/chips-media/wave5/w
> > > > > > > > > > > > > +++ ave5
> > > > > > > > > > > > > +++ .h
> > > > > > > > > > > > > @@ -56,6 +56,9 @@ int
> > > > > > > > > > > > > wave5_vpu_get_version(struct vpu_device
> > > > > > > > > > > > > *vpu_dev, u32 *revision);
> > > > > > > > > > > > >
> > > > > > > > > > > > >  int wave5_vpu_init(struct device *dev, u8 *fw,
> > > > > > > > > > > > > size_t size);
> > > > > > > > > > > > >
> > > > > > > > > > > > > +int wave5_vpu_sleep_wake(struct device *dev,
> > > > > > > > > > > > > +bool i_sleep_wake, const
> > > > > > > > > > > > uint16_t *code,
> > > > > > > > > > > > > +			 size_t size);
> > > > > > > > > > > > > +
> > > > > > > > > > > > >  int wave5_vpu_reset(struct device *dev, enum
> > > > > > > > > > > > > sw_reset_mode reset_mode);
> > > > > > > > > > > > >
> > > > > > > > > > > > >  int wave5_vpu_build_up_dec_param(struct
> > > > > > > > > > > > > vpu_instance *inst, struct dec_open_param
> > > > > > > > > > > > > *param);
> > > > > > > > > > >
> > > > > > > > >
> > > > > > >
> > > >
> >