Try removing C24. See if that helps. Gerald
On Sat, Dec 7, 2013 at 7:01 AM, <[email protected]> wrote: > We are experiencing the same issue, using the A5 version. Roughly 1% to 3% > of the times on boot up, the unit fails to find the PHY. On next boot up > works fine.On very very rare occasions, it will fail to find the PHY 2x in > a row, but haven't seen that in a few days now since started driving > SYS_Resetn as below. Before started driving the Sys_Resetn line, wold see > it miss in the 10+% range. > > The startup SYS_Resetn glitch from the CPU has been observed on multiple > units. To counter that we drove the SYS_Resetn line low { open collector } > for 400 msec with occasional improvements, but the problem has never really > gone away. Using the external open collector reset, we have also added an > adiditonal 4K7 pullup to 3V3. We are also trying driving the line with an > active 3V3 device rather than depending on the pullup.. > > Don't think see any issues with the way 3V3 is coming up. > > Dave > > > On Tuesday, 26 November 2013 17:49:47 UTC-5, Gerald wrote: > >> I am just now looking at this issue. The A6 revision was not put in place >> to fix this issue. >> >> Gerald >> >> >> >> On Tue, Nov 26, 2013 at 4:22 PM, AndrewTaneGlen <[email protected]>wrote: >> >>> Hello, >>> >>> I have noticed very rare cases (~1/50) of the ethernet phy on the >>> Beaglebone Black not being detected on boot, and requiring a hard reset (as >>> opposed to calling 'reset' from the command line) to get it to work/be >>> detected again. >>> >>> This problem has been mentioned in a couple of other threads (below) >>> concerning different topics (i.e. problems getting the BBB to boot, and the >>> ethernet phy 'dying' some time after initially working fine), with no >>> solution/workaround for this specific problem being suggested - so I >>> thought I'd start a thread specifically for it. >>> https://groups.google.com/forum/#!msg/beagleboard/ >>> Vp4pxwHm8BU/Iaw3p5xm0MoJ >>> https://groups.google.com/forum/#!topic/beagleboard/aXv6An1xfqI >>> >>> In the first thread mlc/Mike discussed his response to the problem as >>> follows: >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> *"I had issues with the network not coming up on boot, and it was >>> traced down to problems with the SYS_RESETn line. I had a level translator >>> connected to SYS_RESETn, to drive a 5V chip. It was powered by a 5V rail. >>> If the 5V rail powered up "differently" than the 3.3V rail (not sure of the >>> exact relationship), I guess it pulled the SYS_RESETn line to weird levels >>> that affected the network chip but not the main processor. I'm now using a >>> GPIO to drive the external 5V chip now, instead of the SYS_RESETn >>> line. Anyway, the moral is be very, very careful with SYS_RESETn, because >>> it can cause hard-to-trace problems with networking.*" >>> >>> I see that the A6 Revision of the Beaglebone Black has some changes to >>> the SYS_RESETn line: >>> >>> "*Based on notification from TI, in random instances there could be a >>> glitch in the SYS_RESETn signal from the processor where the SYS_RESETn >>> signal was taken high for a momentary amount of time before it was supposed >>> to. To prevent this, the signal was ORed with the PORZn (Power On reset).* >>> " (http://elinux.org/Beagleboard:BeagleBoneBlack# >>> Revision_A6_.28Production_Version.29) >>> >>> Is it likely that this modification will improve/resolve the issue I am >>> seeing with the ethernt phy not resetting/powering-up correctly?, seeing as >>> the SYS_RESETn signal also feeds into the nRST pin on the ethernet phy (The >>> SYS_RESETn line is left untouched in my application). >>> >>> >>> Some additional observations from dmesg concerning this use: >>> >>> On a good phy boot I see the following: >>> [ 2.810749] davinci_mdio 4a101000.mdio: davinci mdio revision 1.6 >>> [ 2.817206] davinci_mdio 4a101000.mdio: detected phy mask fffffffe >>> [ 2.833517] libphy: 4a101000.mdio: probed >>> [ 2.837871] davinci_mdio 4a101000.mdio: phy[0]: device >>> 4a101000.mdio:00, driver unknown >>> >>> Followed later by: >>> [ 21.286920] net eth0: initializing cpsw version 1.12 (0) >>> [ 21.301166] net eth0: phy found : id is : 0x7c0f1 >>> >>> On a 'bad phy' boot I see the following (differences highlighted): >>> [ 2.806763] davinci_mdio 4a101000.mdio: davinci mdio revision 1.6 >>> [ 2.813213] davinci_mdio 4a101000.mdio: detected phy mask *fffffffb* >>> [ 2.829512] libphy: 4a101000.mdio: probed >>> [ 2.833875] davinci_mdio 4a101000.mdio: phy[2]: device >>> 4a101000.mdio:02, driver unknown >>> >>> Followed later by: >>> [ 21.346861] net eth0: initializing cpsw version 1.12 (0) >>> [ 21.354379] *libphy: PHY 4a101000.mdio:00 not found* >>> [ 21.359469] *net eth0: phy 4a101000.mdio:00 not found on slave 0* >>> >>> >>> So it looks like the 'davinci_mdio_reset' function see the phy in both >>> instances, but reports differently on the bad boot. I am not sure what to >>> make of this. >>> >>> I am using the Debian 7.2 Rootfs and the 'RobertCNelson' kernel >>> '3.12.0-bone8'. >>> >>> >>> >>> Regards, >>> Andrew. >>> >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >> >> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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