On Wed, 7 Feb 2024, Ilpo Järvinen wrote: > > > > Because if it is constantly picking another speed, it would mean you get > > > > LBMS set over and over again, no? If that happens 34-35 times per second, > > > > it should be set already again when we get into that quirk because there > > > > was some wait before it gets called. > > > > > > I'll see if I can experiment with the hardware over the next couple of > > > days and come back with my findings. > > > > Okay thanks. > > One point I'd be very interested to know if the link actually comes up > successfully (even if briefly) because this has large implications whether > the quirk can actually be invoked from the bandwidth controller code. That was more than a couple of days, sorry about it. I have now been able to verify that LBMS keeps getting reasserted over and over again as the device goes through the infinite link training dance. I haven't ever observed the link to become active in the course. Here's a short log of commands repeatedly entered at the command prompt: # setpci -s 02:03.0 CAP_EXP+0x12.W 5011 # setpci -s 02:03.0 CAP_EXP+0x12.W 5812 # setpci -s 02:03.0 CAP_EXP+0x12.W 5811 # setpci -s 02:03.0 CAP_EXP+0x12.W 5812 # setpci -s 02:03.0 CAP_EXP+0x12.W 5011 # setpci -s 02:03.0 CAP_EXP+0x12.W 5811 # setpci -s 02:03.0 CAP_EXP+0x12.W 5811 # setpci -s 02:03.0 CAP_EXP+0x12.W 5812 # setpci -s 02:03.0 CAP_EXP+0x12.W 5812 # setpci -s 02:03.0 CAP_EXP+0x12.W 5811 # setpci -s 02:03.0 CAP_EXP+0x12.W 5811 # setpci -s 02:03.0 CAP_EXP+0x12.W 5812 # setpci -s 02:03.0 CAP_EXP+0x12.W 5812 # setpci -s 02:03.0 CAP_EXP+0x12.W 5811 As you can see the Link Training bit oscillates as I previously reported and noted in the introduction to `pcie_failed_link_retrain', and also the Current Link Speed field flips between 2.5GT/s and 5GT/s. HTH, Maciej
