* struct ethtool_coalesce - coalescing parameters for IRQs and stats updates
* @cmd: ETHTOOL_{G,S}COALESCE
* @rx_coalesce_usecs: How many usecs to delay an RX interrupt after
- * a packet arrives. If 0, only @rx_max_coalesced_frames is used.
- * @rx_max_coalesced_frames: How many packets to delay an RX interrupt
- * after a packet arrives. If 0, only @rx_coalesce_usecs is used.
+ * a packet arrives.
+ * @rx_max_coalesced_frames: Maximum number of packets to receive
+ * before an RX interrupt.
* @rx_coalesce_usecs_irq: Same as @rx_coalesce_usecs, except that
* this value applies while an IRQ is being serviced by the host.
* @rx_max_coalesced_frames_irq: Same as @rx_max_coalesced_frames,
* except that this value applies while an IRQ is being serviced
* by the host.
* @tx_coalesce_usecs: How many usecs to delay a TX interrupt after
- * a packet is sent. If 0, only @tx_max_coalesced_frames
- * is used.
- * @tx_max_coalesced_frames: How many packets to delay a TX interrupt
- * after a packet is sent. If 0, only @tx_coalesce_usecs is
- * used.
+ * a packet is sent.
+ * @tx_max_coalesced_frames: Maximum number of packets to be sent
+ * before a TX interrupt.
* @tx_coalesce_usecs_irq: Same as @tx_coalesce_usecs, except that
* this value applies while an IRQ is being serviced by the host.
* @tx_max_coalesced_frames_irq: Same as @tx_max_coalesced_frames,
* @pkt_rate_low: Threshold for low packet rate (packets per second).
* @rx_coalesce_usecs_low: How many usecs to delay an RX interrupt after
* a packet arrives, when the packet rate is below @pkt_rate_low.
- * @rx_max_coalesced_frames_low: How many packets to delay an RX interrupt
- * after a packet arrives, when the packet rate is below @pkt_rate_low.
+ * @rx_max_coalesced_frames_low: Maximum number of packets to be received
+ * before an RX interrupt, when the packet rate is below @pkt_rate_low.
* @tx_coalesce_usecs_low: How many usecs to delay a TX interrupt after
* a packet is sent, when the packet rate is below @pkt_rate_low.
- * @tx_max_coalesced_frames_low: How many packets to delay a TX interrupt
- * after a packet is sent, when the packet rate is below @pkt_rate_low.
+ * @tx_max_coalesced_frames_low: Maximum nuumber of packets to be sent before
+ * a TX interrupt, when the packet rate is below @pkt_rate_low.
* @pkt_rate_high: Threshold for high packet rate (packets per second).
* @rx_coalesce_usecs_high: How many usecs to delay an RX interrupt after
* a packet arrives, when the packet rate is above @pkt_rate_high.
- * @rx_max_coalesced_frames_high: How many packets to delay an RX interrupt
- * after a packet arrives, when the packet rate is above @pkt_rate_high.
+ * @rx_max_coalesced_frames_high: Maximum number of packets to be received
+ * before an RX interrupt, when the packet rate is above @pkt_rate_high.
* @tx_coalesce_usecs_high: How many usecs to delay a TX interrupt after
* a packet is sent, when the packet rate is above @pkt_rate_high.
- * @tx_max_coalesced_frames_high: How many packets to delay a TX interrupt
- * after a packet is sent, when the packet rate is above @pkt_rate_high.
+ * @tx_max_coalesced_frames_high: Maximum number of packets to be sent before
+ * a TX interrupt, when the packet rate is above @pkt_rate_high.
* @rate_sample_interval: How often to do adaptive coalescing packet rate
* sampling, measured in seconds. Must not be zero.
*
- * It is illegal to set both usecs and max frames to zero as this
- * would cause interrupts to never be generated.
+ * Each pair of (usecs, max_frames) fields specifies this exit
+ * condition for interrupt coalescing:
+ * (usecs > 0 && time_since_first_completion >= usecs) ||
+ * (max_frames > 0 && completed_frames >= max_frames)
+ * It is illegal to set both usecs and max_frames to zero as this
+ * would cause interrupts to never be generated. To disable
+ * coalescing, set usecs = 0 and max_frames = 1.
*
* Adaptive RX/TX coalescing is an algorithm implemented by some
* drivers to improve latency under low packet rates and improve
git.openpandora.org / pandora-kernel.git / blobdiff