From: Miquel Raynal Date: Tue, 25 Jan 2022 12:25:40 +0000 (+0100) Subject: net: mac802154: Explain the use of ieee802154_wake/stop_queue() X-Git-Tag: v5.18-rc1~136^2~388^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c265a3a6690b093e542aceb4a7bf8bf6c577e42b;p=thirdparty%2Fkernel%2Flinux.git net: mac802154: Explain the use of ieee802154_wake/stop_queue() It is not straightforward to the newcomer that a single skb can currently be sent at a time and that the internal process is to stop the queue when processing a frame before re-enabling it. Make this clear by documenting the ieee802154_wake/stop_queue() helpers. Signed-off-by: Miquel Raynal Acked-by: Alexander Aring Link: https://lore.kernel.org/r/20220125122540.855604-4-miquel.raynal@bootlin.com Signed-off-by: Stefan Schmidt --- diff --git a/include/net/mac802154.h b/include/net/mac802154.h index d524ffb9eb257..2c3bbc6645ba9 100644 --- a/include/net/mac802154.h +++ b/include/net/mac802154.h @@ -464,6 +464,12 @@ void ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, * ieee802154_wake_queue - wake ieee802154 queue * @hw: pointer as obtained from ieee802154_alloc_hw(). * + * Tranceivers usually have either one transmit framebuffer or one framebuffer + * for both transmitting and receiving. Hence, the core currently only handles + * one frame at a time for each phy, which means we had to stop the queue to + * avoid new skb to come during the transmission. The queue then needs to be + * woken up after the operation. + * * Drivers should use this function instead of netif_wake_queue. */ void ieee802154_wake_queue(struct ieee802154_hw *hw); @@ -472,6 +478,12 @@ void ieee802154_wake_queue(struct ieee802154_hw *hw); * ieee802154_stop_queue - stop ieee802154 queue * @hw: pointer as obtained from ieee802154_alloc_hw(). * + * Tranceivers usually have either one transmit framebuffer or one framebuffer + * for both transmitting and receiving. Hence, the core currently only handles + * one frame at a time for each phy, which means we need to tell upper layers to + * stop giving us new skbs while we are busy with the transmitted one. The queue + * must then be stopped before transmitting. + * * Drivers should use this function instead of netif_stop_queue. */ void ieee802154_stop_queue(struct ieee802154_hw *hw);