ethtool: Clarify use of size field for ETHTOOL_GRXFHINDIR
In order to find out the device's RX flow hash table size, ethtool
initially uses ETHTOOL_GRXFHINDIR with a buffer size of zero. This
must be supported, but it is not necessary to support any other user
buffer size less than the device table size.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 20db5b27..0ec2fd4 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -543,8 +543,9 @@
/**
* struct ethtool_rxfh_indir - command to get or set RX flow hash indirection
* @cmd: Specific command number - %ETHTOOL_GRXFHINDIR or %ETHTOOL_SRXFHINDIR
- * @size: On entry, the array size of the user buffer. On return from
- * %ETHTOOL_GRXFHINDIR, the array size of the hardware indirection table.
+ * @size: On entry, the array size of the user buffer, which may be zero
+ * for %ETHTOOL_GRXFHINDIR. On return from %ETHTOOL_GRXFHINDIR, the
+ * array size of the hardware indirection table.
* @ring_index: RX ring/queue index for each hash value
*/
struct ethtool_rxfh_indir {