Re: [PATCH v2 1/2] spi: Add hook on suspend/resume for spi master

Grant Likely
2010-11-10T15:58:28Z

On Wed, Nov 10, 2010 at 11:32:54AM +0100, Gregory CLEMENT wrote:
> Some spi masters need to do some actions when system is going to suspend
> or when it will be resumed.
> Spi driver offer possibility to handle suspend and resume only for device.
> Spi master will do its suspend actions after the devices and will do
> its resume action before the devices.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

As stated in my reply to patch 2, this looks to be working around a
bug in the omap spi_master driver. It does not make sense to hook
into the spi_device suspend/resume path to fix it.

g.

> ---
> drivers/spi/spi.c | 14 ++++++++++++++
> include/linux/spi/spi.h | 5 +++++
> 2 files changed, 19 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 709c836..1094aef 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -106,6 +106,11 @@ static int spi_suspend(struct device *dev,
> pm_message_t message)
> {
> int value = 0;
> struct spi_driver *drv = to_spi_driver(dev->driver);
> + struct spi_device *spi_dev = to_spi_device(dev);
> + struct spi_master *master = NULL;
> +
> + if (spi_dev)
> + master = spi_dev->master;
> /* suspend will stop irqs and dma; no more i/o */
> if (drv) {
> @@ -114,6 +119,9 @@ static int spi_suspend(struct device *dev,
> pm_message_t message)
> else
> dev_dbg(dev, "... can't suspend\n");
> }
> + if (master && master->suspend )
> + master->suspend(spi_dev);
> +
> return value;
> }
> @@ -121,7 +129,11 @@ static int spi_resume(struct device *dev)
> {
> int value = 0;
> struct spi_driver *drv = to_spi_driver(dev->driver);
> + struct spi_device *spi_dev = to_spi_device(dev);
> + struct spi_master *master = NULL;
> + if (spi_dev)
> + master = spi_dev->master;
> /* resume may restart the i/o queue */
> if (drv) {
> if (drv->resume)
> @@ -129,6 +141,8 @@ static int spi_resume(struct device *dev)
> else
> dev_dbg(dev, "... can't resume\n");
> }
> + if (master && master->resume )
> + master->resume(spi_dev);
> return value;
> }
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index b4d7710..e98c630 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -307,6 +307,11 @@ struct spi_master {
> /* called on release() to free memory provided by spi_master */
> void (*cleanup)(struct spi_device *spi);
> +
> + /* called on suspend() and resume() if spi_master has to do
> + * some actions */
> + void (*suspend)(struct spi_device *spi);
> + void (*resume)(struct spi_device *spi);
> };
> static inline void *spi_master_get_devdata(struct spi_master *master)
> --
> 1.7.0.4
>
>