diff options
Diffstat (limited to 'target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch b/target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch new file mode 100644 index 0000000000..fbbaae1d2b --- /dev/null +++ b/target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch @@ -0,0 +1,94 @@ +From da5bc1832b325b15e4cca3b63861ecf48be870ef Mon Sep 17 00:00:00 2001 +From: Russell King <rmk+kernel@armlinux.org.uk> +Date: Sun, 10 Jan 2021 10:58:32 +0000 +Subject: [PATCH] net: sfp: cope with SFPs that set both LOS normal and LOS + inverted + +The SFP MSA defines two option bits in byte 65 to indicate how the +Rx_LOS signal on SFP pin 8 behaves: + +bit 2 - Loss of Signal implemented, signal inverted from standard + definition in SFP MSA (often called "Signal Detect"). +bit 1 - Loss of Signal implemented, signal as defined in SFP MSA + (often called "Rx_LOS"). + +Clearly, setting both bits results in a meaningless situation: it would +mean that LOS is implemented in both the normal sense (1 = signal loss) +and inverted sense (0 = signal loss). + +Unfortunately, there are modules out there which set both bits, which +will be initially interpret as "inverted" sense, and then, if the LOS +signal changes state, we will toggle between LINK_UP and WAIT_LOS +states. + +Change our LOS handling to give well defined behaviour: only interpret +these bits as meaningful if exactly one is set, otherwise treat it as +if LOS is not implemented. + +Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> +Reviewed-by: Andrew Lunn <andrew@lunn.ch> +Link: https://lore.kernel.org/r/E1kyYQa-0004iR-CU@rmk-PC.armlinux.org.uk +Signed-off-by: Jakub Kicinski <kuba@kernel.org> +--- + drivers/net/phy/sfp.c | 36 ++++++++++++++++++++++-------------- + 1 file changed, 22 insertions(+), 14 deletions(-) + +--- a/drivers/net/phy/sfp.c ++++ b/drivers/net/phy/sfp.c +@@ -1430,15 +1430,19 @@ static void sfp_sm_link_down(struct sfp + + static void sfp_sm_link_check_los(struct sfp *sfp) + { +- unsigned int los = sfp->state & SFP_F_LOS; ++ const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED); ++ const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL); ++ __be16 los_options = sfp->id.ext.options & (los_inverted | los_normal); ++ bool los = false; + + /* If neither SFP_OPTIONS_LOS_INVERTED nor SFP_OPTIONS_LOS_NORMAL +- * are set, we assume that no LOS signal is available. ++ * are set, we assume that no LOS signal is available. If both are ++ * set, we assume LOS is not implemented (and is meaningless.) + */ +- if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED)) +- los ^= SFP_F_LOS; +- else if (!(sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL))) +- los = 0; ++ if (los_options == los_inverted) ++ los = !(sfp->state & SFP_F_LOS); ++ else if (los_options == los_normal) ++ los = !!(sfp->state & SFP_F_LOS); + + if (los) + sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0); +@@ -1448,18 +1452,22 @@ static void sfp_sm_link_check_los(struct + + static bool sfp_los_event_active(struct sfp *sfp, unsigned int event) + { +- return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) && +- event == SFP_E_LOS_LOW) || +- (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) && +- event == SFP_E_LOS_HIGH); ++ const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED); ++ const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL); ++ __be16 los_options = sfp->id.ext.options & (los_inverted | los_normal); ++ ++ return (los_options == los_inverted && event == SFP_E_LOS_LOW) || ++ (los_options == los_normal && event == SFP_E_LOS_HIGH); + } + + static bool sfp_los_event_inactive(struct sfp *sfp, unsigned int event) + { +- return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) && +- event == SFP_E_LOS_HIGH) || +- (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) && +- event == SFP_E_LOS_LOW); ++ const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED); ++ const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL); ++ __be16 los_options = sfp->id.ext.options & (los_inverted | los_normal); ++ ++ return (los_options == los_inverted && event == SFP_E_LOS_HIGH) || ++ (los_options == los_normal && event == SFP_E_LOS_LOW); + } + + static void sfp_sm_fault(struct sfp *sfp, unsigned int next_state, bool warn) |