Hi, Thank you for the review. Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> 於 2024年9月11日 週三 下午11:05寫道： > > On 11.9.2024 8.17, Kuangyi Chiang wrote: > > Performing a stability stress test on a USB3.0 2.5G ethernet adapter > > results in errors like this: > > > > [ 91.441469] r8152 2-3:1.0 eth3: get_registers -71 > > [ 91.458659] r8152 2-3:1.0 eth3: get_registers -71 > > [ 91.475911] r8152 2-3:1.0 eth3: get_registers -71 > > [ 91.493203] r8152 2-3:1.0 eth3: get_registers -71 > > [ 91.510421] r8152 2-3:1.0 eth3: get_registers -71 > > > > The r8152 driver will periodically issue lots of control-IN requests > > to access the status of ethernet adapter hardware registers during > > the test. > > > > This happens when the xHCI driver enqueue a control TD (which cross > > over the Link TRB between two ring segments, as shown) in the endpoint > > zero's transfer ring. Seems the Etron xHCI host can not perform this > > TD correctly, causing the USB transfer error occurred, maybe the upper > > driver retry that control-IN request can solve problem, but not all > > drivers do this. > > > > | | > > ------- > > | TRB | Setup Stage > > ------- > > | TRB | Link > > ------- > > ------- > > | TRB | Data Stage > > ------- > > | TRB | Status Stage > > ------- > > | | > > > > What if the link TRB is between Data and Status stage, does that > case work normally? I am not sure, I don't encounter this case, maybe OK. > > > To work around this, the xHCI driver should enqueue a No Op TRB if > > next available TRB is the Link TRB in the ring segment, this can > > prevent the Setup and Data Stage TRB to be breaked by the Link TRB. > > There are some hosts that need the 'Chain' bit set in the Link TRB, > does that work in this case? No, it doesn't work. It seems to be a hardware issue. > > Thanks > Mathias > Thanks, Kuangyi Chiang
