Re: [PATCH v2] dma: dw: Add suspend and resume handling for PCI mode DW_DMAC.

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Sat, 2014-03-15 at 02:02 +0800, Chew Chiau Ee wrote:
> From: Chew, Chiau Ee <chiau.ee.chew@intel.com>
> 
> This is to disable/enable DW_DMAC hw during late suspend/early resume.
> Since DMA is providing service to other clients (eg: SPI, HSUART),
> we need to ensure DMA suspends after the clients and resume
> before the clients are active.

Thanks for an update!

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

P.S. It seems a material is for v3.16?

> 
> Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
> ---
>  v2 changelog:
>  * Change suspend_noirq and resume_noirq callback to suspend_late
>    and resume_early.
> 
>  drivers/dma/dw/pci.c |   33 +++++++++++++++++++++++++++++++++
>  1 files changed, 33 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/dma/dw/pci.c b/drivers/dma/dw/pci.c
> index 755cc6b..fec59f1 100644
> --- a/drivers/dma/dw/pci.c
> +++ b/drivers/dma/dw/pci.c
> @@ -75,6 +75,36 @@ static void dw_pci_remove(struct pci_dev *pdev)
>  		dev_warn(&pdev->dev, "can't remove device properly: %d\n", ret);
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +
> +static int dw_pci_suspend_late(struct device *dev)
> +{
> +	struct pci_dev *pci = to_pci_dev(dev);
> +	struct dw_dma_chip *chip = pci_get_drvdata(pci);
> +
> +	return dw_dma_suspend(chip);
> +};
> +
> +static int dw_pci_resume_early(struct device *dev)
> +{
> +	struct pci_dev *pci = to_pci_dev(dev);
> +	struct dw_dma_chip *chip = pci_get_drvdata(pci);
> +
> +	return dw_dma_resume(chip);
> +};
> +
> +#else /* !CONFIG_PM_SLEEP */
> +
> +#define dw_pci_suspend_late	NULL
> +#define dw_pci_resume_early	NULL
> +
> +#endif /* !CONFIG_PM_SLEEP */
> +
> +static const struct dev_pm_ops dw_pci_dev_pm_ops = {
> +	.suspend_late = dw_pci_suspend_late,
> +	.resume_early = dw_pci_resume_early,
> +};
> +
>  static DEFINE_PCI_DEVICE_TABLE(dw_pci_id_table) = {
>  	/* Medfield */
>  	{ PCI_VDEVICE(INTEL, 0x0827), (kernel_ulong_t)&dw_pci_pdata },
> @@ -95,6 +125,9 @@ static struct pci_driver dw_pci_driver = {
>  	.id_table	= dw_pci_id_table,
>  	.probe		= dw_pci_probe,
>  	.remove		= dw_pci_remove,
> +	.driver	= {
> +		.pm	= &dw_pci_dev_pm_ops,
> +	},
>  };
>  
>  module_pci_driver(dw_pci_driver);


-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy