On 20 September 2013 11:48, Ulf Hansson <[email protected]> wrote:
> We want to give user space provision to fully consume a card
> insert/remove event, when the event was caused by a wakeup irq.
>
> By signaling the wakeup event for a time of 5 s for devices configured
> as wakeup capable, we likely will be prevent a sleep long enough to let
> user space consume the event.
>
> To enable this feature, host drivers must thus configure their devices
> as wakeup capable.
>
> This is a reworked implementation of the old wakelocks for the mmc
> subsystem, originally authored by Colin Cross and San Mehat for the
> Android kernel. Zoran Markovic shall also be given cred for recently
> re-trying to upstream this feature.
>
> Cc: San Mehat <[email protected]>
> Cc: Colin Cross <[email protected]>
> Cc: John Stultz <[email protected]>
> Cc: Zoran Markovic <[email protected]>
> Signed-off-by: Ulf Hansson <[email protected]>
> ---
>
> This patch has just been compile tested, since I at very moment did not
> have a good board to test it on. I am working on that.
>
> Any help in testing this patch is thus greatly appreciated. While
> testing also don't forget to enable the host device as wakeup capable.
> Use "device_init_wakeup" from the host probe function.
Testing now done on a ux500 SoC. Changes done to configuring card
detect irq as wakeup. Sysfs nodes is behaving as expected. :-)
>
> ---
> drivers/mmc/core/core.c | 39 +++++++++++++++++++++++++++------------
> 1 file changed, 27 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index bf18b6b..3e8229e 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -23,6 +23,7 @@
> #include <linux/log2.h>
> #include <linux/regulator/consumer.h>
> #include <linux/pm_runtime.h>
> +#include <linux/pm_wakeup.h>
> #include <linux/suspend.h>
> #include <linux/fault-inject.h>
> #include <linux/random.h>
> @@ -1723,6 +1724,28 @@ void mmc_detach_bus(struct mmc_host *host)
> mmc_bus_put(host);
> }
>
> +static void _mmc_detect_change(struct mmc_host *host, unsigned long delay,
> + bool cd_irq)
> +{
> +#ifdef CONFIG_MMC_DEBUG
> + unsigned long flags;
> + spin_lock_irqsave(&host->lock, flags);
> + WARN_ON(host->removed);
> + spin_unlock_irqrestore(&host->lock, flags);
> +#endif
> +
> + /*
> + * If the device is configured as wakeup, we prevent a new sleep for
> + * 5 s to give provision for user space to consume the event.
> + */
> + if (cd_irq && !(host->caps & MMC_CAP_NEEDS_POLL) &&
> + device_can_wakeup(mmc_dev(host)))
> + pm_wakeup_event(mmc_dev(host), 5000);
> +
> + host->detect_change = 1;
> + mmc_schedule_delayed_work(&host->detect, delay);
> +}
> +
> /**
> * mmc_detect_change - process change of state on a MMC socket
> * @host: host which changed state.
> @@ -1735,16 +1758,8 @@ void mmc_detach_bus(struct mmc_host *host)
> */
> void mmc_detect_change(struct mmc_host *host, unsigned long delay)
> {
> -#ifdef CONFIG_MMC_DEBUG
> - unsigned long flags;
> - spin_lock_irqsave(&host->lock, flags);
> - WARN_ON(host->removed);
> - spin_unlock_irqrestore(&host->lock, flags);
> -#endif
> - host->detect_change = 1;
> - mmc_schedule_delayed_work(&host->detect, delay);
> + _mmc_detect_change(host, delay, true);
> }
> -
> EXPORT_SYMBOL(mmc_detect_change);
>
> void mmc_init_erase(struct mmc_card *card)
> @@ -2423,7 +2438,7 @@ int mmc_detect_card_removed(struct mmc_host *host)
> * rescan handle the card removal.
> */
> cancel_delayed_work(&host->detect);
> - mmc_detect_change(host, 0);
> + _mmc_detect_change(host, 0, false);
> }
> }
>
> @@ -2505,7 +2520,7 @@ void mmc_start_host(struct mmc_host *host)
> mmc_power_off(host);
> else
> mmc_power_up(host);
> - mmc_detect_change(host, 0);
> + _mmc_detect_change(host, 0, false);
> }
>
> void mmc_stop_host(struct mmc_host *host)
> @@ -2724,7 +2739,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
> spin_lock_irqsave(&host->lock, flags);
> host->rescan_disable = 0;
> spin_unlock_irqrestore(&host->lock, flags);
> - mmc_detect_change(host, 0);
> + _mmc_detect_change(host, 0, false);
>
> }
>
> --
> 1.7.9.5
>
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