Re: [PATCH 2/2] dmaengine: shdma: add runtime- and system-level power management

Koul, Vinod
2011-05-02T08:35:18Z

On Fri, 2011-04-29 at 19:09 +0200, Guennadi Liakhovetski wrote:
> This patch extends and fixes runtime power management in the shdma
> driver to support powering down the DMA controller and adds support
> for system-level suspend and resume.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
> drivers/dma/shdma.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/dma/shdma.h | 1 +
> 2 files changed, 69 insertions(+), 0 deletions(-)
>

>
> +static int sh_dmae_runtime_suspend(struct device *dev)
> +{
> + return 0;
> +}
Don't you need to initialize you device on resume...????

> +
> +static int sh_dmae_runtime_resume(struct device *dev)
> +{
> + struct sh_dmae_device *shdev = dev_get_drvdata(dev);
> +
> + return sh_dmae_rst(shdev);
> +}
> +
> +#ifdef CONFIG_PM
This should be removed...
> +static int sh_dmae_suspend(struct device *dev)
> +{
> + struct sh_dmae_device *shdev = dev_get_drvdata(dev);
> + int i;
> +
> + for (i = 0; i < shdev->pdata->channel_num; i++) {
> + struct sh_dmae_chan *sh_chan = shdev->chan[i];
> + if (sh_chan->descs_allocated)
> + sh_chan->pm_error = pm_runtime_put_sync(dev);
> + }
> +
> + return 0;
> +}
> +
> +static int sh_dmae_resume(struct device *dev)
> +{
> + struct sh_dmae_device *shdev = dev_get_drvdata(dev);
> + int i;
> +
> + for (i = 0; i < shdev->pdata->channel_num; i++) {
> + struct sh_dmae_chan *sh_chan = shdev->chan[i];
> + struct sh_dmae_slave *param = sh_chan->common.private;
> +
> + if (!sh_chan->descs_allocated)
> + continue;
> +
> + if (!sh_chan->pm_error)
> + pm_runtime_get_sync(dev);
> +
> + if (param) {
> + const struct sh_dmae_slave_config *cfg = param->config;
> + dmae_set_dmars(sh_chan, cfg->mid_rid);
> + dmae_set_chcr(sh_chan, cfg->chcr);
> + } else {
> + dmae_init(sh_chan);
> + }
> + }
> +
> + return 0;
> +}
> +#else
> +#define sh_dmae_suspend NULL
> +#define sh_dmae_resume NULL
> +#endif
> +
> +const struct dev_pm_ops sh_dmae_pm = {
> + .suspend = sh_dmae_suspend,
> + .resume = sh_dmae_resume,
> + .runtime_suspend = sh_dmae_runtime_suspend,
> + .runtime_resume = sh_dmae_runtime_resume,
> +};
> +
> static struct platform_driver sh_dmae_driver = {
> .remove = __exit_p(sh_dmae_remove),
> .shutdown = sh_dmae_shutdown,
> .driver = {
> .owner = THIS_MODULE,
> .name = "sh-dma-engine",
> + .pm = &sh_dmae_pm,
> },
> };
>
> diff --git a/drivers/dma/shdma.h b/drivers/dma/shdma.h
> index 52e4fb1..3f9d3cd 100644
> --- a/drivers/dma/shdma.h
> +++ b/drivers/dma/shdma.h
> @@ -37,6 +37,7 @@ struct sh_dmae_chan {
> int id; /* Raw id of this channel */
> u32 __iomem *base;
> char dev_id[16]; /* unique name per DMAC of channel */
> + int pm_error;
> };
>
> struct sh_dmae_device {

And please remember to CC maintainers...

--
~Vinod