Messages in this thread | | | Date | Wed, 5 Feb 2020 11:33:43 +0200 | From | Andy Shevchenko <> | Subject | Re: [PATCH v2 2/2] net-sysfs: Ensure begin/complete are called in speed_show() and duplex_show() |
| |
On Wed, Feb 05, 2020 at 10:23:45AM +0100, Michal Kubecek wrote: > On Wed, Feb 05, 2020 at 11:06:38AM +0200, Andy Shevchenko wrote: > > On Wed, Feb 05, 2020 at 04:16:16PM +0800, Kai-Heng Feng wrote: > > > Device like igb gets runtime suspended when there's no link partner. We > > > can't get correct speed under that state: > > > $ cat /sys/class/net/enp3s0/speed > > > 1000 > > > > > > In addition to that, an error can also be spotted in dmesg: > > > [ 385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost > > > > > > It's because the igb device doesn't get runtime resumed before calling > > > get_link_ksettings(). > > > > > > So let's use a new helper to call begin() and complete() like what > > > dev_ethtool() does, to runtime resume/suspend or power up/down the > > > device properly. > > > > > > Once this fix is in place, igb can show the speed correctly without link > > > partner: > > > $ cat /sys/class/net/enp3s0/speed > > > -1 > > > > What is the meaning of -1? Does it tells us "Hey, something is bad in hardware > > I can't tell you the speed" or does it imply anything else? > > It's SPEED_UNKNOWN constant printed with "%d" template. > > > Wouldn't be better to report 0? > > > > Where is the documentation part of this ABI change? > > It's not an ABI change, /sys/class/net/*/speed already shows -1 when the > device reports SPEED_UNKNOWN. The only change is that after this patch, > igb driver reports SPEED_UNKNOWN rather than an outdated value if there > is no link.
Thanks for elaboration. Perhaps add a couple of words to the commit message that there is no ABI changes.
-- With Best Regards, Andy Shevchenko
| |