Re: [PATCH 3/4] net: sfp: assume that LOS is not implemented if both LOS normal and inverted is set

Russell King - ARM Linux admin
2020-12-30T16:14:12Z

On Wed, Dec 30, 2020 at 04:47:54PM +0100, Pali Rohár wrote:
> Some GPON SFP modules (e.g. Ubiquiti U-Fiber Instant) have set both
> SFP_OPTIONS_LOS_INVERTED and SFP_OPTIONS_LOS_NORMAL bits in their EEPROM.
>
> Such combination of bits is meaningless so assume that LOS signal is not
> implemented.
>
> This patch fixes link carrier for GPON SFP module Ubiquiti U-Fiber Instant.
>
> Co-developed-by: Russell King <rmk+kernel@armlinux.org.uk>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

No, this is not co-developed. The patch content is exactly what _I_
sent you, only the commit description is your own.

> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
> drivers/net/phy/sfp.c | 36 ++++++++++++++++++++++--------------
> 1 file changed, 22 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
> index 73f3ecf15260..d47485ed239c 100644
> --- a/drivers/net/phy/sfp.c
> +++ b/drivers/net/phy/sfp.c
> @@ -1475,15 +1475,19 @@ static void sfp_sm_link_down(struct sfp *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);
> @@ -1493,18 +1497,22 @@ static void sfp_sm_link_check_los(struct sfp *sfp)
>
> 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)
> --
> 2.20.1
>
>

--
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