On Fri, Jul 18, 2025 at 09:55:42AM +0800, Shawn Lin wrote: > Hi Geraldo, > > 在 2025/06/11 星期三 3:05, Geraldo Nascimento 写道: > > After almost 30 days of battling with RK3399 buggy PCIe on my Rock Pi > > N10 through trial-and-error debugging, I finally got positive results > > with enumeration on the PCI bus for both a Realtek 8111E NIC and a > > Samsung PM981a SSD. > > > > The NIC was connected to a M.2->PCIe x4 riser card and it would get > > stuck on Polling.Compliance, without breaking electrical idle on the > > Host RX side. The Samsung PM981a SSD is directly connected to M.2 > > connector and that SSD is known to be quirky (OEM... no support) > > and non-functional on the RK3399 platform. > > > > The Samsung SSD was even worse than the NIC - it would get stuck on > > Detect.Active like a bricked card, even though it was fully functional > > via USB adapter. > > > > It seems both devices benefit from retrying Link Training if - big if > > here - PERST# is not toggled during retry. > > > > I didn't see this error before especially given RTL8111 NIC is widelly > used by customers. Hi Shawn, great to hear from you! Notice that my board exposes PCIe only via NVMe connector, and not directly via a proper PCIe connector, so it is necessary for me to adapt with inexpensive riser card that exposes proper PCIe connector. I say this because while I don't doubt that the RTL8111 NIC works out-of-the-box for boards that directly expose PCIe connector, the combination of riser card plus NIC has a similar effect - though not entirely equal, as described above - of connecting known good SSDs that simply refuse to work with Rockchip-IP PCIe. I admit that patch 1 looks a little crazy, but is has the effect of enabling use of presently non-working devices or combination of devices on this IP, at least on the board I have access to. > > Could you help tried this? > [1] apply your patch 3 first Sure, I'm always open for testing, but could you clarify the patch 3 part? AFAIK this series of mine only has 2 patches, so I'm a little confused about exactly which patch to apply as a preliminary step. Also, since you're asking me to test some code, I think it is only fair if I ask you to test my code, too. It shouldn't be too hard for you to find a otherwise working NVMe SSD that refuses to complete link training with current code. Connect this SSD please to a RK3399 board and let us know if my proposed code change does anything to ameliorate the long-standing issue of SSD that refuses to cooperate. Thank you, Geraldo Nascimento
