[PATCH v2] mfd: vexpress: Handle pending config transactions

[tixy@linaro.org (Jon Medhurst (Tixy))]

On Thu, 2013-04-25 at 18:14 +0100, Pawel Moll wrote:
> The config transactions "scheduler" was hopelessly broken,
> repeating completed transaction instead of picking up
> next pending one.
> 
> Fixed now. Also improved debug messages.
> 
> Signed-off-by: Pawel Moll <pawel.moll@arm.com>

Yes, looks really fixed now. :-)

Reviewed-by: Jon Medhurst <tixy@linaro.org>

> ---
>  drivers/mfd/vexpress-config.c |   35 +++++++++++++++++++++--------------
>  1 file changed, 21 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/mfd/vexpress-config.c b/drivers/mfd/vexpress-config.c
> index 3c1723aa..84ce6b9 100644
> --- a/drivers/mfd/vexpress-config.c
> +++ b/drivers/mfd/vexpress-config.c
> @@ -184,13 +184,14 @@ static int vexpress_config_schedule(struct vexpress_config_trans *trans)
>  
>  	spin_lock_irqsave(&bridge->transactions_lock, flags);
>  
> -	vexpress_config_dump_trans("Executing", trans);
> -
> -	if (list_empty(&bridge->transactions))
> +	if (list_empty(&bridge->transactions)) {
> +		vexpress_config_dump_trans("Executing", trans);
>  		status = bridge->info->func_exec(trans->func->func,
>  				trans->offset, trans->write, trans->data);
> -	else
> +	} else {
> +		vexpress_config_dump_trans("Queuing", trans);
>  		status = VEXPRESS_CONFIG_STATUS_WAIT;
> +	}
>  
>  	switch (status) {
>  	case VEXPRESS_CONFIG_STATUS_DONE:
> @@ -212,25 +213,31 @@ void vexpress_config_complete(struct vexpress_config_bridge *bridge,
>  {
>  	struct vexpress_config_trans *trans;
>  	unsigned long flags;
> +	const char *message = "Completed";
>  
>  	spin_lock_irqsave(&bridge->transactions_lock, flags);
>  
>  	trans = list_first_entry(&bridge->transactions,
>  			struct vexpress_config_trans, list);
> -	vexpress_config_dump_trans("Completed", trans);
> -
>  	trans->status = status;
> -	list_del(&trans->list);
>  
> -	if (!list_empty(&bridge->transactions)) {
> -		vexpress_config_dump_trans("Pending", trans);
> +	do {
> +		vexpress_config_dump_trans(message, trans);
> +		list_del(&trans->list);
> +		complete(&trans->completion);
>  
> -		bridge->info->func_exec(trans->func->func, trans->offset,
> -				trans->write, trans->data);
> -	}
> -	spin_unlock_irqrestore(&bridge->transactions_lock, flags);
> +		if (list_empty(&bridge->transactions))
> +			break;
> +
> +		trans = list_first_entry(&bridge->transactions,
> +				struct vexpress_config_trans, list);
> +		vexpress_config_dump_trans("Executing pending", trans);
> +		trans->status = bridge->info->func_exec(trans->func->func,
> +				trans->offset, trans->write, trans->data);
> +		message = "Finished pending";
> +	} while (trans->status == VEXPRESS_CONFIG_STATUS_DONE);
>  
> -	complete(&trans->completion);
> +	spin_unlock_irqrestore(&bridge->transactions_lock, flags);
>  }
>  EXPORT_SYMBOL(vexpress_config_complete);
>