On 11/04/16 15:51, Felipe Balbi wrote: > > Hi, > > Roger Quadros <rogerq@xxxxxx> writes: > > <snip> > >>> I don't have this text anywhere so I don't know. Is this something TI >>> came up with or Synopsys ? Unless I can see a document (preferrably from >>> Synopsys) stating this, I can't really accept $subject. >> >> OK. I'll try to find out if there is an official document about this. >> >>> >>> Another question is: if all it takes is an extra SoftReset, why don't we >>> just reset it during probe() if max_speed < SUPER and we're running on >>> rev < 2.20a ? BTW, which revision of the IP is on AM57x/DRA7x ? >> >> The issue might happen on any Run/Stop transition so not sure if doing it >> SoftReset just at probe fixes anything. >> >> On DRA7x it is rev 2.02a. > > oh, same block as OMAP5 ES2.0 :-( > >>>>> question is, then: How are you sure that resetting the device actually >>>>> solves the issue ? Did you really hit the metastability problem and >>>>> noted that it works after a soft-reset ? How did you verify that >>>> >>>> I don't know if it solves the issue or not. It was suggested by >>>> Synopsis to TI's silicon team. >>> >>> now that's a bummer ;-) >>> >>>> I never hit the metastability problem detection condition in my >>>> overnight tests (i.e. LTDB_LINK_STATE != 4). >>> >>> overnight is not enough. You need to keep this running for weeks. >> >> how many weeks is acceptable for you? I can run for that long, no problem. >> And what if the issue doesn't happen in that time frame, would you still >> consider this case? > > Well, there's always the possibility we have never triggered the issue > to start with :-) What happens if you remove the the current workaround, > set maximum-speed to high-speed and constantly toggle run/stop bit > (there's a soft-connect file under the UDC's directory in sysfs). Can > you ever cause the problems ? I had tried a with max-speed set to high-speed and a script that just reloads g_zero. That should toggle Run/Stop right? Running this overnight didn't cause any problems. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
