Re: [PATCH net,stable] phy: sfp: fix high power modules without diag mode
From: Bjørn Mork <bjorn@mork.no>
Date: 2021-12-03 13:55:29
"Russell King (Oracle)" [off-list ref] writes:
quoted hunk ↗ jump to hunk
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