Re: [PATCH v2 0/7] Introduce SpacemiT K1 PCIe phy and host controller

[Aurelien Jarno <aurelien@aurel32.net>]

Hi Alex,

On 2025-10-17 11:21, Alex Elder wrote:
> On 10/16/25 11:47 AM, Aurelien Jarno wrote:
> > Hi Alex,
> > 
> > On 2025-10-13 10:35, Alex Elder wrote:
> > > This series introduces a PHY driver and a PCIe driver to support PCIe
> > > on the SpacemiT K1 SoC.  The PCIe implementation is derived from a
> > > Synopsys DesignWare PCIe IP.  The PHY driver supports one combination
> > > PCIe/USB PHY as well as two PCIe-only PHYs.  The combo PHY port uses
> > > one PCIe lane, and the other two ports each have two lanes.  All PCIe
> > > ports operate at 5 GT/second.
> > > 
> > > The PCIe PHYs must be configured using a value that can only be
> > > determined using the combo PHY, operating in PCIe mode.  To allow
> > > that PHY to be used for USB, the calibration step is performed by
> > > the PHY driver automatically at probe time.  Once this step is done,
> > > the PHY can be used for either PCIe or USB.
> > > 
> > > Version 2 of this series incorporates suggestions made during the
> > > review of version 1.  Specific highlights are detailed below.
> > 
> > With the issues mentioned in patch 4 fixed, this patchset works fine for
> > me. That said I had to disable ASPM by passing pcie_aspm=off on the
> > command line, as it is now enabled by default since 6.18-rc1 [1]. At
> > this stage, I am not sure if it is an issue with my NVME drive or an
> > issue with the controller.
> 
> Can you describe what symptoms you had that required you to pass
> "pcie_aspm=off" on the kernel command line?
> 
> I see these lines in my boot log related to ASPM (and added by
> the commit you link to), for both pcie1 and pcie2:
> 
>   pci 0000:01:00.0: ASPM: DT platform, enabling L0s-up L0s-dw L1 AS
> PM-L1.1 ASPM-L1.2 PCI-PM-L1.1 PCI-PM-L1.2
>   pci 0000:01:00.0: ASPM: DT platform, enabling ClockPM
> 
>   . . .
> 
>   nvme nvme0: pci function 0000:01:00.0
>   nvme 0000:01:00.0: enabling device (0000 -> 0002)
>   nvme nvme0: allocated 64 MiB host memory buffer (16 segments).
>   nvme nvme0: 8/0/0 default/read/poll queues
>    nvme0n1: p1
> 
> My NVMe drive on pcie1 works correctly.
>   https://www.crucial.com/ssd/p3/CT1000P3SSD8
> 
>   root@bananapif3:~# df /a
>   Filesystem     1K-blocks     Used Available Use% Mounted on
>   /dev/nvme0n1p1 960302804 32063304 879385040   4% /a
>   root@bananapif3:~#

Sorry for the delay, it took me time to test some more things and 
different SSDs. First of all I still see the issue with your v3 on top 
of v6.18-rc3, which includes some fixes for ASPM support [1].

I have tried 3 different SSDs, none of them are working, but the 
symptoms are different, although all related with ASPM (pcie_aspm=off 
workarounds the issue).

With a Fox Spirit PM18 SSD (Silicon Motion, Inc. SM2263EN/SM2263XT 
controller), I do not have more than this:
[    5.196723] nvme nvme0: pci function 0000:01:00.0
[    5.198843] nvme 0000:01:00.0: enabling device (0000 -> 0002)

With a WD Blue SN570 SSD, I get this:
[    5.199513] nvme nvme0: pci function 0000:01:00.0
[    5.201653] nvme 0000:01:00.0: enabling device (0000 -> 0002)
[    5.270334] nvme nvme0: allocated 32 MiB host memory buffer (8 segments).
[    5.277624] nvme nvme0: 8/0/0 default/read/poll queues
[   19.192350] nvme nvme0: using unchecked data buffer
[   48.108400] nvme nvme0: controller is down; will reset: CSTS=0xffffffff, PCI_STATUS=0x10
[   48.113885] nvme nvme0: Does your device have a faulty power saving mode enabled?
[   48.121346] nvme nvme0: Try "nvme_core.default_ps_max_latency_us=0 pcie_aspm=off pcie_port_pm=off" and report a bug
[   48.176878] nvme0n1: I/O Cmd(0x2) @ LBA 0, 8 blocks, I/O Error (sct 0x3 / sc 0x71) 
[   48.181926] I/O error, dev nvme0n1, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
[   48.243670] nvme 0000:01:00.0: enabling device (0000 -> 0002)
[   48.246914] nvme nvme0: Disabling device after reset failure: -19
[   48.280495] Buffer I/O error on dev nvme0n1, logical block 0, async page read


Finally with a PNY CS1030 SSD (Phison PS5015-E15 controller), I get this:
[    5.215631] nvme nvme0: pci function 0000:01:00.0
[    5.220435] nvme 0000:01:00.0: enabling device (0000 -> 0002)
[    5.329565] nvme nvme0: allocated 64 MiB host memory buffer (16 segments).
[   66.540485] nvme nvme0: I/O tag 28 (401c) QID 0 timeout, disable controller
[   66.585245] nvme 0000:01:00.0: probe with driver nvme failed with error -4

Note that I also tested this latest SSD on a VisionFive 2 board with exactly
the same kernel (I just moved the SSD and booted), and it works fine with ASPM
enabled (confirmed with lspci).

> I basically want to know if there's something I should do with this
> driver to address this.  (Mani, can you explain?)

I am not sure on my side how to debug that. What I know is that it is 
linked to ASPM L1, L0 works fine. In other words the SSDs work fine with 
this patch:

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 79b9651584737..1a134ec68b591 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -801,8 +801,8 @@ static void pcie_aspm_override_default_link_state(struct pcie_link_state *link)
 	if (of_have_populated_dt()) {
 		if (link->aspm_support & PCIE_LINK_STATE_L0S)
 			link->aspm_default |= PCIE_LINK_STATE_L0S;
-		if (link->aspm_support & PCIE_LINK_STATE_L1)
-			link->aspm_default |= PCIE_LINK_STATE_L1;
+//		if (link->aspm_support & PCIE_LINK_STATE_L1)
+//			link->aspm_default |= PCIE_LINK_STATE_L1;
 		override = link->aspm_default & ~link->aspm_enabled;
 		if (override)
 			pci_info(pdev, "ASPM: default states%s%s\n",

I can test more things if needed, but I don't know where to start.

Regards
Aurelien

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=df5192d9bb0e38bf831fb93e8026e346aa017ca8

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                     http://aurel32.net

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