[REGRESSION] mainline/master: Apalis iMX6 no longer boots

[Hongxing Zhu (OSS)]

NXP Confidential
> -----Original Message-----
> From: Francesco Dolcini <francesco at dolcini.it>
> Sent: Thursday, August 13, 2026 3:47 PM
> To: Franz Schnyder <fra.schnyder at gmail.com>; Hongxing Zhu
> <hongxing.zhu at nxp.com>
> Cc: Francesco Dolcini <francesco at dolcini.it>; Hongxing Zhu (OSS)
> <hongxing.zhu at oss.nxp.com>; Leonardo Costa <leoreis.costa at gmail.com>;
> Bjorn Helgaas <helgaas at kernel.org>; robh at kernel.org; krzk+dt at kernel.org;
> conor+dt at kernel.org; Frank Li <frank.li at nxp.com>; s.hauer at pengutronix.de;
> kernel at pengutronix.de; festevam at gmail.com; leonardo.costa at toradex.com;
> devicetree at vger.kernel.org; imx at lists.linux.dev; linux-arm-
> kernel at lists.infradead.org; linux-kernel at vger.kernel.org;
> regressions at lists.linux.dev; Sherry Sun <sherry.sun at nxp.com>; Manivannan
> Sadhasivam <mani at kernel.org>; linux-pci at vger.kernel.org
> Subject: Re: [REGRESSION] mainline/master: Apalis iMX6 no longer boots
>
> On Thu, Aug 13, 2026 at 09:34:01AM +0200, Franz Schnyder wrote:
> > On Wed, Aug 12, 2026 at 08:54:13AM +0200, Francesco Dolcini wrote:
> > > So, unless I did some mistake in my manual test, the issue is
> > > related to the specific PCIe card or some other subtle difference I cannot see
> yet.
> > >
> > > For the record, the failure was detected by our CI/CD, and it is
> > > systematically reproduced on multiple hardware boards.
> > >
> > > Leonardo: any chance you can test with the same PCIe board that is failing?
> >
> > I reproduced the issue on my setup (eval board + same PCIe card as in our
> CI/CD).
> >
> > root at apalis-imx6-11486042:~# lspci
> > root at apalis-imx6-11486042:~# dmesg | grep pcie
> > [    0.162860] imx6q-pcie 1ffc000.pcie: host bridge /soc/pcie at 1ffc000 ranges:
> > [    0.162974] imx6q-pcie 1ffc000.pcie:       IO 0x0001f80000..0x0001f8ffff ->
> 0x0000000000
> > [    0.163043] imx6q-pcie 1ffc000.pcie:      MEM 0x0001000000..0x0001efffff -
> > 0x0001000000
> > [    0.163193] imx6q-pcie 1ffc000.pcie: config reg[1] 0x01f00000 == cpu
> 0x01f00000
> > [    0.505056] imx6q-pcie 1ffc000.pcie: iATU: unroll F, 4 ob, 4 ib, align 64K,
> limit 4G
> > [    0.505230] imx6q-pcie 1ffc000.pcie: Link: Only Gen1 is enabled
> > [    1.508173] imx6q-pcie 1ffc000.pcie: Link failed to come up. LTSSM:
> POLL_CONFIG
> > [    1.508314] imx6q-pcie 1ffc000.pcie: probe with driver imx6q-pcie failed
> with error -110
> >
> > After applying the new sequence proposed by Zhu, the PCIe card comes up.
> >
> > root at apalis-imx6-11486042:~# lspci
> > 00:00.0 PCI bridge: Synopsys, Inc. DWC_usb3 / PCIe bridge (rev 01)
> > 01:00.0 SATA controller: ASMedia Technology Inc. ASM1061/ASM1062
> > Serial ATA Controller (rev 02) root at apalis-imx6-11486042:~# dmesg | grep
> pcie
> > [    0.162515] imx6q-pcie 1ffc000.pcie: host bridge /soc/pcie at 1ffc000 ranges:
> > [    0.162636] imx6q-pcie 1ffc000.pcie:       IO 0x0001f80000..0x0001f8ffff ->
> 0x0000000000
> > [    0.162702] imx6q-pcie 1ffc000.pcie:      MEM 0x0001000000..0x0001efffff -
> > 0x0001000000
> > [    0.162828] imx6q-pcie 1ffc000.pcie: config reg[1] 0x01f00000 == cpu
> 0x01f00000
> > [    0.488893] imx6q-pcie 1ffc000.pcie: iATU: unroll F, 4 ob, 4 ib, align 64K,
> limit 4G
> > [    0.489033] imx6q-pcie 1ffc000.pcie: Link: Only Gen1 is enabled
> > [    0.591333] imx6q-pcie 1ffc000.pcie: PCIe Gen.1 x1 link up
> > [    0.591967] imx6q-pcie 1ffc000.pcie: PCI host bridge to bus 0000:00
> > [    0.602947] pcieport 0000:00:00.0: PME: Signaling with IRQ 291
> > [    0.603534] pcieport 0000:00:00.0: AER: enabled with IRQ 291
> >
> > I'm completely out of the loop on this whole issue and I only helped
> > out to test the patch. However, I wanted to add that before applying
> > Zhu's proposed sequence, I could only reproduce the issue by power
> > cycling the module, as rebooting alone did not trigger the issue.
>
> Interesting. This might explain why I couldn’t reproduce the issue in my setup,
> rather than the difference being caused by the specific PCIe card.
>
> Franz: thanks for the test.
>
> Richard: will you submit a formal patch, so we try to finally fix this issue?  I
> guess it's now too late for 7.2, so be sure to cc:stable and have a fixes tag.
Thanks for your reminder and Franz' tests.
I'm preparing the fix patch now.

Best Regards
Richard Zhu
>
> Francesco