Re: [PATCH RFC 0/2] PCI: rockchip-host: Retry training and hot-reset a JMB585 on RK3399

[Shawn Lin <shawn.lin@rock-chips.com>]

在 2026/11/09 星期一 7:05, Igor Velkov 写道:
> Hi Shawn,
> 
> Thanks. Deskew makes no difference. Helios64, x2, bind/unbind, variants
> alternating every cycle, bad link bring-ups:
> 
>    defaults 6/104, auto deskew off + trim 0xf: 5/104
>    defaults 6/104, magnitude off: 6/104
> 
> Your mail has the magnitude at 0xb, but TRM V1.3 part 2, 17.6.10.1 has
> TX_TERMINATION_TRIM there and DESKEW_MAGNITUDE at 0xc, so I wrote 0xc.

Sorry, my typo.

> 
> DEBUG_DATA_OUT did show something. With Debug Mux Control (0x208) = 5,
> share of samples with in_dllp0_data_valid set, 100 ms window after hot reset:
> 
>    good bring-ups 0.16% (99), bad bring-ups 51% (3, range 45-53)
> 
> The first training looks the same: 0.15% (97) against 47% (5). mgmt_dllp_error,
> crc32_error and in_tlp_error stay 0 in all of them. With the mux at 4,
> start_replay, replay timeout and dl_protocol_error stay 0 too.
> 
> So in a bad bring-up the RC receives a constant error-free stream of DLLPs.
> I read that as the JMB585 repeating flow control init because it does not
> get what the RC sends, but this bus does not show the DLLP type. It would put
> the fault in the RC to JMB585 direction, on x2 only.
> 
> Is there an RC transmitter setting worth trying for that, such as swing or
> de-emphasis? If not, I will stop looking for the cause here.
> 

Reg 0xa is for swing, it says: "This value should be set to (64-56*0 .9/
VDD09) depending on actual voltage of VDD09"

But de-emphasis is fixed in each kind of bus speed.

> Igor
>