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| author | Ben Hutchings <bhutchings@solarflare.com> | 2011-08-15 14:09:22 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-08-16 16:36:15 -0700 |
| commit | a27fc96b0317b732b68b5f781bbdeb56ab5082a8 (patch) | |
| tree | f52b25ab7a0005f0bd1da684873c8de8c1f3b7cf /include/linux/ethtool.h | |
| parent | acf42a2a575777681fee45ed59d7140be38e9142 (diff) | |
| download | lwn-a27fc96b0317b732b68b5f781bbdeb56ab5082a8.tar.gz lwn-a27fc96b0317b732b68b5f781bbdeb56ab5082a8.zip | |
ethtool: Note common alternate exit condition for interrupt coalescing
Many implementations ignore the value of max_frames and do not
treat usecs == 0 as special. Document this as deprecated.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/ethtool.h')
| -rw-r--r-- | include/linux/ethtool.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 42378b34ae8f..3829712ccc05 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -173,6 +173,12 @@ struct ethtool_eeprom { * would cause interrupts to never be generated. To disable * coalescing, set usecs = 0 and max_frames = 1. * + * Some implementations ignore the value of max_frames and use the + * condition: + * time_since_first_completion >= usecs + * This is deprecated. Drivers for hardware that does not support + * counting completions should validate that max_frames == !rx_usecs. + * * Adaptive RX/TX coalescing is an algorithm implemented by some * drivers to improve latency under low packet rates and improve * throughput under high packet rates. Some drivers only implement |