Re: [PATCH V3] MMC: PM: add suspend/resume in atmel-mci

Felipe Balbi
2011-07-04T11:06:58Z

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Hi,

On Mon, Jul 04, 2011 at 01:38:25PM +0200, Nicolas Ferre wrote:
> Take care of slots while going to suspend state.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
> V3: take care of each slot SUSPENDED state
> (adding a status bit in the slot "flags")
> V2: move to pm_ops
>
> drivers/mmc/host/atmel-mci.c | 60 ++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 60 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
> index aa8039f..ed63bcd 100644
> --- a/drivers/mmc/host/atmel-mci.c
> +++ b/drivers/mmc/host/atmel-mci.c
> @@ -203,6 +203,7 @@ struct atmel_mci_slot {
> #define ATMCI_CARD_PRESENT 0
> #define ATMCI_CARD_NEED_INIT 1
> #define ATMCI_SHUTDOWN 2
> +#define ATMCI_SUSPENDED 3
>
> int detect_pin;
> int wp_pin;
> @@ -1878,10 +1879,69 @@ static int __exit atmci_remove(struct platform_device *pdev)
> return 0;
> }
>
> +#ifdef CONFIG_PM
> +static int atmci_suspend(struct device *dev)
> +{
> + struct atmel_mci *host = dev_get_drvdata(dev);
> + int i;
> +
> + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
> + struct atmel_mci_slot *slot = host->slot[i];
> + int ret;
> +
> + if (!slot)
> + continue;
> + ret = mmc_suspend_host(slot->mmc);
> + if (ret < 0) {
> + while (--i >= 0) {
> + slot = host->slot[i];
> + if (slot
> + && test_bit(ATMCI_SUSPENDED, &slot->flags)) {
> + mmc_resume_host(host->slot[i]->mmc);
> + clear_bit(ATMCI_SUSPENDED, &slot->flags);
> + }
> + }
> + return ret;
> + } else {
> + set_bit(ATMCI_SUSPENDED, &slot->flags);
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int atmci_resume(struct device *dev)
> +{
> + struct atmel_mci *host = dev_get_drvdata(dev);
> + int i;
> + int ret = 0;
> +
> + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
> + struct atmel_mci_slot *slot = host->slot[i];
> + int err;
> +
> + slot = host->slot[i];
> + if (!slot)
> + continue;
> + if (!test_bit(ATMCI_SUSPENDED, &slot->flags))
> + continue;
> + err = mmc_resume_host(slot->mmc);
> + if (err < 0)
> + ret = err;
> + else
> + clear_bit(ATMCI_SUSPENDED, &slot->flags);
> + }
> +
> + return ret;
> +}
> +#endif
> +static SIMPLE_DEV_PM_OPS(atmci_pm, atmci_suspend, atmci_resume);

if you disable CONFIG_PM this won't work. atmci_resume and atmci_suspend
will be undefined.

> static struct platform_driver atmci_driver = {
> .remove = __exit_p(atmci_remove),
> .driver = {
> .name = "atmel_mci",
> + .pm = &atmci_pm,

this pointer will also be invalid.

what most people do is:

#ifdef CONFIG_PM

suspend()
resume()

static SIMPLE_DEV_PM_OPS(atmci_pm, suspend, resume);

#define DEV_PM_OPS (&atmci_pm)
#else
#define DEV_PM_OPS NULL
#endif

--
balbi

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