No Capes! http://www.youtube.com/watch?v=Jy2YhxXn7NY
On 3/20/2014 10:47 AM, Gerald Coley wrote: > A cape. I hate capes. Maybe on the next revision I will just disable all of > them! > > Thanks! > > Gerald > > > > On Thu, Mar 20, 2014 at 10:32 AM, Kees k <[email protected]> wrote: > >> Haha, I was looking at the wrong file (BB white A6). Sorry for the >> trouble; it seems our cape causes this difference between A5C and A6. >> >> On Tuesday, November 26, 2013 11:22:42 PM UTC+1, AndrewTaneGlen 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/d/optout. >> > -- Charles Steinkuehler [email protected] -- 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/d/optout.
