Re: [PATCH 58/65] OMAPDSS: APPLY: add wait_pending_extra_info_updates()

[Archit Taneja <a0393947@ti.com>]

On Tuesday 22 November 2011 02:51 PM, Tomi Valkeinen wrote:
> Add wait_pending_extra_info_updates() function which can be used to wait
> until any extra_info changes have been taken into use by the hardware.
> This can be only called when holding the apply mutex, so that other
> threads cannot insert new extra_info changes.
>
> This will be used to handle fifo-configurations.
>
> Signed-off-by: Tomi Valkeinen<tomi.valkeinen@ti.com>
> ---
>   drivers/video/omap2/dss/apply.c |   70 +++++++++++++++++++++++++++++++++++++++
>   1 files changed, 70 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/video/omap2/dss/apply.c b/drivers/video/omap2/dss/apply.c
> index 76b5b02..75db522 100644
> --- a/drivers/video/omap2/dss/apply.c
> +++ b/drivers/video/omap2/dss/apply.c
> @@ -106,6 +106,7 @@ static struct {
>   static spinlock_t data_lock;
>   /* lock for blocking functions */
>   static DEFINE_MUTEX(apply_lock);
> +static DECLARE_COMPLETION(extra_updated_completion);
>
>   static void dss_register_vsync_isr(void);
>
> @@ -232,6 +233,70 @@ static bool need_go(struct omap_overlay_manager *mgr)
>   	return false;
>   }
>
> +/* returns true if an extra_info field is currently being updated */
> +static bool extra_info_update_ongoing(void)
> +{
> +	const int num_ovls = omap_dss_get_num_overlays();
> +	struct ovl_priv_data *op;
> +	struct omap_overlay *ovl;
> +	struct mgr_priv_data *mp;
> +	int i;
> +	bool eid;
> +
> +	for (i = 0; i<  num_ovls; ++i) {
> +		ovl = omap_dss_get_overlay(i);
> +		op = get_ovl_priv(ovl);
> +
> +		if (!op->enabled)
> +			continue;
> +
> +		mp = get_mgr_priv(ovl->manager);
> +
> +		if (!mp->enabled)
> +			continue;
> +
> +		eid = op->extra_info_dirty || op->shadow_extra_info_dirty;
> +
> +		if (!eid)
> +			continue;
> +
> +		if (ovl_manual_update(ovl)&&  !mp->updating)
> +			continue;
> +
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
> +/* wait until no extra_info updates are pending */
> +static void wait_pending_extra_info_updates(void)
> +{
> +	bool updating;
> +	unsigned long flags;
> +	unsigned long t;
> +
> +	spin_lock_irqsave(&data_lock, flags);
> +
> +	updating = extra_info_update_ongoing();
> +
> +	if (!updating) {
> +		spin_unlock_irqrestore(&data_lock, flags);
> +		return;
> +	}
> +
> +	init_completion(&extra_updated_completion);
> +
> +	spin_unlock_irqrestore(&data_lock, flags);
> +
> +	t = msecs_to_jiffies(500);
> +	wait_for_completion_timeout(&extra_updated_completion, t);
> +
> +	updating = extra_info_update_ongoing();
> +
> +	WARN_ON(updating);
> +}

This function isn't used, are you planning to use it later?

Archit

> +
>   int dss_mgr_wait_for_go(struct omap_overlay_manager *mgr)
>   {
>   	unsigned long timeout = msecs_to_jiffies(500);
> @@ -553,6 +618,7 @@ static void dss_apply_irq_handler(void *data, u32 mask)
>   {
>   	const int num_mgrs = dss_feat_get_num_mgrs();
>   	int i;
> +	bool extra_updating;
>
>   	spin_lock(&data_lock);
>
> @@ -582,6 +648,10 @@ static void dss_apply_irq_handler(void *data, u32 mask)
>
>   	dss_write_regs();
>
> +	extra_updating = extra_info_update_ongoing();
> +	if (!extra_updating)
> +		complete_all(&extra_updated_completion);
> +
>   	if (!need_isr())
>   		dss_unregister_vsync_isr();
>