From: "Bjørn Mork" <bjorn@mork•no>
To: "Russell King (Oracle)" <linux@armlinux•org.uk>
Cc: "Jakub Kicinski" <kuba@kernel•org>,
netdev@vger•kernel.org, 照山周一郎 <teruyama@springboard-inc•jp>
Subject: Re: [PATCH net,stable] phy: sfp: fix high power modules without diag mode
Date: Fri, 03 Dec 2021 14:55:17 +0100 [thread overview]
Message-ID: <877dclkd2y.fsf@miraculix.mork.no> (raw)
In-Reply-To: <YaoUW9KHyEQOt46b@shell.armlinux.org.uk> (Russell King's message of "Fri, 3 Dec 2021 12:58:03 +0000")
"Russell King (Oracle)" <linux@armlinux•org.uk> writes:
> Thinking a little more, how about this:
>
> drivers/net/phy/sfp.c | 25 +++++++++++++++++++++----
> 1 file changed, 21 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
> index 51a1da50c608..4c900d063b19 100644
> --- a/drivers/net/phy/sfp.c
> +++ b/drivers/net/phy/sfp.c
> @@ -1752,17 +1752,20 @@ static int sfp_sm_probe_for_phy(struct sfp *sfp)
> static int sfp_module_parse_power(struct sfp *sfp)
> {
> u32 power_mW = 1000;
> + bool supports_a2;
>
> if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_POWER_DECL))
> power_mW = 1500;
> if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_HIGH_POWER_LEVEL))
> power_mW = 2000;
>
> + supports_a2 = sfp->id.ext.sff8472_compliance !=
> + SFP_SFF8472_COMPLIANCE_NONE ||
> + sfp->id.ext.diagmon & SFP_DIAGMON_DDM;
> +
> if (power_mW > sfp->max_power_mW) {
> /* Module power specification exceeds the allowed maximum. */
> - if (sfp->id.ext.sff8472_compliance ==
> - SFP_SFF8472_COMPLIANCE_NONE &&
> - !(sfp->id.ext.diagmon & SFP_DIAGMON_DDM)) {
> + if (!supports_a2) {
> /* The module appears not to implement bus address
> * 0xa2, so assume that the module powers up in the
> * indicated mode.
> @@ -1779,11 +1782,24 @@ static int sfp_module_parse_power(struct sfp *sfp)
> }
> }
>
> + if (power_mW <= 1000) {
> + /* Modules below 1W do not require a power change sequence */
> + return 0;
> + }
> +
> + if (!supports_a2) {
> + /* The module power level is below the host maximum and the
> + * module appears not to implement bus address 0xa2, so assume
> + * that the module powers up in the indicated mode.
> + */
> + return 0;
> + }
> +
> /* If the module requires a higher power mode, but also requires
> * an address change sequence, warn the user that the module may
> * not be functional.
> */
> - if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE && power_mW > 1000) {
> + if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE) {
> dev_warn(sfp->dev,
> "Address Change Sequence not supported but module requires %u.%uW, module may not be functional\n",
> power_mW / 1000, (power_mW / 100) % 10);
Looks nice to me at least. But I don't have the hardware to test it.
Bjørn
next prev parent reply other threads:[~2021-12-03 13:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 7:39 [PATCH net,stable] phy: sfp: fix high power modules without diag mode Bjørn Mork
2021-12-03 1:58 ` Jakub Kicinski
2021-12-03 11:54 ` Russell King (Oracle)
2021-12-03 12:58 ` Russell King (Oracle)
2021-12-03 13:55 ` Bjørn Mork [this message]
2021-12-04 12:38 ` Russell King (Oracle)
2021-12-06 10:35 ` Bjørn Mork
2021-12-06 15:39 ` 照山周一郎
2021-12-30 11:43 ` Bjørn Mork
2021-12-30 11:55 ` Russell King (Oracle)
2021-12-30 12:00 ` 照山周一郎
2022-01-15 16:58 ` Christian Lamparter
2022-01-17 14:24 ` Russell King (Oracle)
2022-01-17 14:44 ` Bjørn Mork
2022-01-17 14:49 ` Christian Lamparter
2022-01-18 6:58 ` 照山周一郎
2021-12-03 13:41 ` Bjørn Mork
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