Re: [PATCH V4 3/6] slimbus: Add messaging APIs to slimbus framework

[Mark Brown]

On Sat, Feb 06, 2016 at 11:44:22AM -0700, Sagar Dharia wrote:

> +	spin_lock_irqsave(&ctrl->txn_lock, flags);
> +	msg = ctrl->tid_tbl[tid];
> +	if (msg == NULL || msg->rbuf == NULL) {
> +		spin_unlock_irqrestore(&ctrl->txn_lock, flags);
> +		dev_err(&ctrl->dev, "Got response to invalid TID:%d, len:%d\n",
> +				tid, len);
> +		return;
> +	}
> +	memcpy(msg->rbuf, reply, len);
> +	ctrl->tid_tbl[tid] = NULL;
> +	if (msg->comp_cb)
> +		msg->comp_cb(msg->ctx, 0);
> +	spin_unlock_irqrestore(&ctrl->txn_lock, flags);

Do we need to hold the lock for so long (especially with things like the
memcpy())?  As far as I can tell we only need the lock for this:

> +	msg = ctrl->tid_tbl[tid];
> +	ctrl->tid_tbl[tid] = NULL;

> +	if (mc == SLIM_MSG_MC_REQUEST_CHANGE_VALUE ||
> +		mc == SLIM_MSG_MC_CHANGE_VALUE ||
> +		mc == SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION ||
> +		mc == SLIM_MSG_MC_CLEAR_INFORMATION)
> +		txn->rl += msg->num_bytes;

A switch statement might be nicer here.

Attachment: signature.asc
Description: PGP signature