Re: [PATCH v1 2/3] mailbox: mediatek: implement flush function

[CK Hu]

Hi, Bibby:

On Mon, 2020-02-17 at 17:05 +0800, Bibby Hsieh wrote:
> For client driver which need to reorganize the command buffer, it could
> use this function to flush the send command buffer.
> If the channel doesn't be started (usually in waiting for event), this
> function will abort it directly.
> 

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
> ---
>  drivers/mailbox/mtk-cmdq-mailbox.c | 52 ++++++++++++++++++++++++++++++
>  1 file changed, 52 insertions(+)
> 
> diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
> index 9a6ce9f5a7db..0da5e2dc2c0e 100644
> --- a/drivers/mailbox/mtk-cmdq-mailbox.c
> +++ b/drivers/mailbox/mtk-cmdq-mailbox.c
> @@ -432,10 +432,62 @@ static void cmdq_mbox_shutdown(struct mbox_chan *chan)
>  {
>  }
>  
> +static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
> +{
> +	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
> +	struct cmdq_task_cb *cb;
> +	struct cmdq_cb_data data;
> +	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
> +	struct cmdq_task *task, *tmp;
> +	unsigned long flags;
> +	u32 enable;
> +
> +	spin_lock_irqsave(&thread->chan->lock, flags);
> +	if (list_empty(&thread->task_busy_list))
> +		goto out;
> +
> +	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
> +	if (!cmdq_thread_is_in_wfe(thread))
> +		goto wait;
> +
> +	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
> +				 list_entry) {
> +		cb = &task->pkt->async_cb;
> +		if (cb->cb) {
> +			data.sta = CMDQ_CB_ERROR;
> +			data.data = cb->data;
> +			cb->cb(data);
> +		}
> +		list_del(&task->list_entry);
> +		kfree(task);
> +	}
> +
> +	cmdq_thread_resume(thread);
> +	cmdq_thread_disable(cmdq, thread);
> +	clk_disable(cmdq->clock);
> +
> +out:
> +	spin_unlock_irqrestore(&thread->chan->lock, flags);
> +	return 0;
> +
> +wait:
> +	cmdq_thread_resume(thread);
> +	spin_unlock_irqrestore(&thread->chan->lock, flags);
> +	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_ENABLE_TASK,
> +				      enable, enable == 0, 1, timeout)) {
> +		dev_err(cmdq->mbox.dev, "Fail to wait GCE thread 0x%x done\n",
> +			(u32)(thread->base - cmdq->base));
> +
> +		return -EFAULT;
> +	}
> +	return 0;
> +}
> +
>  static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
>  	.send_data = cmdq_mbox_send_data,
>  	.startup = cmdq_mbox_startup,
>  	.shutdown = cmdq_mbox_shutdown,
> +	.flush = cmdq_mbox_flush,
>  };
>  
>  static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,