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authorAntoine Tenart <antoine.tenart@bootlin.com>2018-05-04 18:21:03 +0300
committerDavid S. Miller <davem@davemloft.net>2018-05-09 03:14:27 +0300
commit2b999ba899059eed00a03d029894a62486e7e2bc (patch)
treea369534f52328b890e90f02b05d2aea6a337427e /drivers/net/phy/sfp-bus.c
parent8d42eada64e4c564d22be61ef68585d4bbaabaa9 (diff)
downloadlinux-2b999ba899059eed00a03d029894a62486e7e2bc.tar.xz
net: phy: sfp: handle cases where neither BR, min nor BR, max is given
When computing the bitrate using values read from an SFP module EEPROM, we use the nominal BR plus BR,min and BR,max to determine the boundaries. But in some cases BR,min and BR,max aren't provided, which led the SFP code to end up having the nominal value for both the minimum and maximum bitrate values. When using a passive cable, the nominal value should be used as the maximum one, and there is no minimum one so we should use 0. Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy/sfp-bus.c')
-rw-r--r--drivers/net/phy/sfp-bus.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index 0381da78d228..b2f4519dfb84 100644
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -132,6 +132,13 @@ void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
br_max = br_nom + br_nom * id->ext.br_min / 100;
br_min = br_nom - br_nom * id->ext.br_min / 100;
}
+
+ /* When using passive cables, in case neither BR,min nor BR,max
+ * are specified, set br_min to 0 as the nominal value is then
+ * used as the maximum.
+ */
+ if (br_min == br_max && id->base.sfp_ct_passive)
+ br_min = 0;
}
/* Set ethtool support from the compliance fields. */