> -----Original Message-----
> From: Vinod Koul <vkoul@xxxxxxxxxx>
> Sent: 2024年12月24日 17:30
> To: Joy Zou <joy.zou@xxxxxxx>
> Cc: Frank Li <frank.li@xxxxxxx>; S.J. Wang <shengjiu.wang@xxxxxxx>;
> imx@xxxxxxxxxxxxxxx; dmaengine@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v1] dmaengine: fsl-edma: add runtime
> suspend/resume support
>
>
>
> On 20-12-24, 10:11, Joy Zou wrote:
> > Introduce runtime suspend and resume support for FSL eDMA. Enable
> > per-channel power domain management to facilitate runtime suspend and
> > resume operations.
> >
> > Implement runtime suspend and resume functions for the eDMA engine and
> > individual channels.
> >
> > Link per-channel power domain device to eDMA per-channel device
> > instead of eDMA engine device. So Power Manage framework manage power
> > state of linked domain device when per-channel device request runtime
> resume/suspend.
> >
> > Trigger the eDMA engine's runtime suspend when all channels are
> > suspended, disabling all common clocks through the runtime PM framework.
> >
> > Signed-off-by: Joy Zou <joy.zou@xxxxxxx>
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> > drivers/dma/fsl-edma-common.c | 15 ++---
> > drivers/dma/fsl-edma-main.c | 115
> ++++++++++++++++++++++++++++++----
> > 2 files changed, 110 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/dma/fsl-edma-common.c
> > b/drivers/dma/fsl-edma-common.c index b7f15ab96855..fcdb53b21f38
> > 100644
> > --- a/drivers/dma/fsl-edma-common.c
> > +++ b/drivers/dma/fsl-edma-common.c
> > @@ -243,9 +243,6 @@ int fsl_edma_terminate_all(struct dma_chan *chan)
> > spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> > vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
> >
> > - if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_PD)
> > - pm_runtime_allow(fsl_chan->pd_dev);
> > -
> > return 0;
> > }
> >
> > @@ -805,8 +802,12 @@ int fsl_edma_alloc_chan_resources(struct
> dma_chan *chan)
> > struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> > int ret;
> >
> > - if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
> > - clk_prepare_enable(fsl_chan->clk);
> > + ret = pm_runtime_get_sync(&fsl_chan->vchan.chan.dev->device);
> > + if (ret < 0) {
> > + dev_err(&fsl_chan->vchan.chan.dev->device,
> "pm_runtime_get_sync() failed\n");
> > + pm_runtime_disable(&fsl_chan->vchan.chan.dev->device);
> > + return ret;
> > + }
> >
> > fsl_chan->tcd_pool = dma_pool_create("tcd_pool",
> chan->device->dev,
> > fsl_edma_drvflags(fsl_chan) &
> FSL_EDMA_DRV_TCD64 ?
> > @@ -819,6 +820,7 @@ int fsl_edma_alloc_chan_resources(struct dma_chan
> > *chan)
> >
> > if (ret) {
> > dma_pool_destroy(fsl_chan->tcd_pool);
> > +
> > + pm_runtime_put_sync_suspend(&fsl_chan->vchan.chan.dev->device);
> > return ret;
> > }
> > }
> > @@ -851,8 +853,7 @@ void fsl_edma_free_chan_resources(struct
> dma_chan *chan)
> > fsl_chan->is_sw = false;
> > fsl_chan->srcid = 0;
> > fsl_chan->is_remote = false;
> > - if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
> > - clk_disable_unprepare(fsl_chan->clk);
> > + pm_runtime_put_sync_suspend(&fsl_chan->vchan.chan.dev->device);
> > }
> >
> > void fsl_edma_cleanup_vchan(struct dma_device *dmadev) diff --git
> > a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c index
> > 60de1003193a..75d6c8984c8e 100644
> > --- a/drivers/dma/fsl-edma-main.c
> > +++ b/drivers/dma/fsl-edma-main.c
> > @@ -420,7 +420,6 @@ MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
> static
> > int fsl_edma3_attach_pd(struct platform_device *pdev, struct
> > fsl_edma_engine *fsl_edma) {
> > struct fsl_edma_chan *fsl_chan;
> > - struct device_link *link;
> > struct device *pd_chan;
> > struct device *dev;
> > int i;
> > @@ -439,24 +438,39 @@ static int fsl_edma3_attach_pd(struct
> platform_device *pdev, struct fsl_edma_eng
> > return -EINVAL;
> > }
> >
> > - link = device_link_add(dev, pd_chan, DL_FLAG_STATELESS |
> > - DL_FLAG_PM_RUNTIME |
> > - DL_FLAG_RPM_ACTIVE);
> > - if (!link) {
> > - dev_err(dev, "Failed to add device_link to %d\n", i);
> > - return -EINVAL;
> > - }
> > -
> > fsl_chan->pd_dev = pd_chan;
> > -
> > - pm_runtime_use_autosuspend(fsl_chan->pd_dev);
> > - pm_runtime_set_autosuspend_delay(fsl_chan->pd_dev,
> 200);
> > - pm_runtime_set_active(fsl_chan->pd_dev);
> > }
> >
> > return 0;
> > }
> >
> > +/* Per channel dma power domain */
> > +static int fsl_edma_chan_runtime_suspend(struct device *dev) {
> > + struct fsl_edma_chan *fsl_chan = dev_get_drvdata(dev);
> > + int ret = 0;
> > +
> > + clk_disable_unprepare(fsl_chan->clk);
> > +
> > + return ret;
>
> Unused ret! drop it
Thanks for your comments!
Will drop it!
>
> > +}
> > +
> > +static int fsl_edma_chan_runtime_resume(struct device *dev) {
> > + struct fsl_edma_chan *fsl_chan = dev_get_drvdata(dev);
> > + int ret;
> > +
> > + ret = clk_prepare_enable(fsl_chan->clk);
> > +
> > + return ret;
>
> how about return clk_prepare_enable()
Yeah! It's better! Will change it.
Thank you very much!
Merry Christmas!
BR
Joy Zou
>
> --
> ~Vinod
