Hi, some trivial comments below.
On Fri, Oct 06, 2017 at 05:51:33PM +0200, srinivas.kandagatla@xxxxxxxxxx wrote:
> From: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
>
> Per slimbus specification, a reconfiguration sequence known as
> 'clock pause' needs to be broadcast over the bus while entering low-
> power mode. Clock-pause is initiated by the controller driver.
> To exit clock-pause, controller typically wakes up the framer device.
> Since wakeup precedure is controller-specific, framework calls it via
> controller's function pointer to invoke it.
>
> Signed-off-by: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
[...]
> @@ -429,6 +444,14 @@ void slim_return_tx(struct slim_controller *ctrl, int err)
> cur.cb(cur.ctx, err);
>
> up(&ctrl->tx_sem);
> + if (!cur.clk_pause && (!cur.need_tid || err)) {
> + /**
This isn't really a kerneldoc comment.
> + * remove runtime-pm vote if this was TX only, or
> + * if there was error during this transaction
> + */
> + pm_runtime_mark_last_busy(ctrl->dev.parent);
> + pm_runtime_put_autosuspend(ctrl->dev.parent);
> + }
> }
> EXPORT_SYMBOL_GPL(slim_return_tx);
>
[...]
> +/**
> + * slim_ctrl_clk_pause: Called by slimbus controller to enter/exit 'clock pause'
> + * Slimbus specification needs this sequence to turn-off clocks for the bus.
> + * The sequence involves sending 3 broadcast messages (reconfiguration
> + * sequence) to inform all devices on the bus.
> + * To exit clock-pause, controller typically wakes up active framer device.
> + * @ctrl: controller requesting bus to be paused or woken up
> + * @wakeup: Wakeup this controller from clock pause.
> + * @restart: Restart time value per spec used for clock pause. This value
> + * isn't used when controller is to be woken up.
> + * This API executes clock pause reconfiguration sequence if wakeup is false.
> + * If wakeup is true, controller's wakeup is called.
> + * For entering clock-pause, -EBUSY is returned if a message txn in pending.
> + */
> +int slim_ctrl_clk_pause(struct slim_controller *ctrl, bool wakeup, u8 restart)
> +{
> + int i, ret = 0;
> + unsigned long flags;
> + struct slim_sched *sched = &ctrl->sched;
> + struct slim_val_inf msg = {0, 0, NULL, NULL, NULL, NULL};
> +
> + DEFINE_SLIM_BCAST_TXN(txn, SLIM_MSG_MC_BEGIN_RECONFIGURATION,
> + 3, SLIM_LA_MANAGER, &msg);
> +
> + if (wakeup == false && restart > SLIM_CLK_UNSPECIFIED)
> + return -EINVAL;
> +
> + mutex_lock(&sched->m_reconf);
> + if (wakeup) {
> + if (sched->clk_state == SLIM_CLK_ACTIVE) {
> + mutex_unlock(&sched->m_reconf);
> + return 0;
> + }
> +
> + /**
ditto
> + * Fine-tune calculation based on clock gear,
> + * message-bandwidth after bandwidth management
> + */
> + ret = wait_for_completion_timeout(&sched->pause_comp,
> + msecs_to_jiffies(100));
> + if (!ret) {
> + mutex_unlock(&sched->m_reconf);
> + pr_err("Previous clock pause did not finish");
> + return -ETIMEDOUT;
> + }
> + ret = 0;
> +
> + /**
ditto
> + * Slimbus framework will call controller wakeup
> + * Controller should make sure that it sets active framer
> + * out of clock pause
> + */
> + if (sched->clk_state == SLIM_CLK_PAUSED && ctrl->wakeup)
> + ret = ctrl->wakeup(ctrl);
> + if (!ret)
> + sched->clk_state = SLIM_CLK_ACTIVE;
> + mutex_unlock(&sched->m_reconf);
> +
> + return ret;
> + }
[...]
Thanks,
Jonathan Neuschäfer
Attachment:
signature.asc
Description: PGP signature
