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

[Hongxing Zhu (OSS)]

> -----Original Message-----
> From: Leonardo Costa <leoreis.costa@xxxxxxxxx>
> Sent: Tuesday, August 11, 2026 2:26 AM
> To: Hongxing Zhu (OSS) <hongxing.zhu@xxxxxxxxxxx>
> Cc: Bjorn Helgaas <helgaas@xxxxxxxxxx>; robh@xxxxxxxxxx;
> krzk+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx; Frank Li <frank.li@xxxxxxx>;
> s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx;
> leonardo.costa@xxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> imx@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; regressions@xxxxxxxxxxxxxxx; Sherry Sun
> <sherry.sun@xxxxxxx>; Manivannan Sadhasivam <mani@xxxxxxxxxx>;
> Hongxing Zhu <hongxing.zhu@xxxxxxx>; linux-pci@xxxxxxxxxxxxxxx
> Subject: Re: [REGRESSION] mainline/master: Apalis iMX6 no longer boots
> 
> On Thu, Jul 16, 2026 at 02:09:19PM -0300, Leonardo Costa wrote:
> > On Thu, Jul 16, 2026 at 02:15:42AM +0000, Hongxing Zhu (OSS) wrote:
> > > Hi Leonardo,
> > >
> > > Would you be able to test this patch on your affected boards? Your
> > > testing would help expedite the merge process and ensure the fix
> > > resolves the boot issue you're experiencing.
> > >
> > > Best Regards
> > > Richard Zhu
> >
> > Hi Richard,
> >
> > Sorry for taking long to respond, I was caught up with something. I
> > tested the patch and it solved the issue. I sent a Tested-by tag there.
> > Thanks for looking into this!
> >
> > Best Regards
> > Leonardo
> 
> Hi Richard,
> 
> That patch might have introduced/exposed a second regression where PCI
> devices are not linked properly during the initialization. Sorry for not catching
> this before, as I didn't have any device connected during the previous test.
Hi Leonardo:
Sorry to hear about that.
I did test commit 7678e81498e2 with one Intel NIC (82574L) connected, and I've
double-checked today based on v7.2-rc7. The PCIe link can be set up properly
on the i.MX6Q Sabresd board in my testing.

Here are the logs:
root@imx6qpdlsolox:~# lspci
00:00.0 PCI bridge: Synopsys, Inc. DWC_usb3 / PCIe bridge (rev 01)
01:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
root@imx6qpdlsolox:~# uname -a
Linux imx6qpdlsolox 7.2.0-rc7 #30 SMP Tue Aug 11 00:21:26 UTC 2026 armv7l GNU/Linux
root@imx6qpdlsolox:~# dmesg | grep pci
[    0.256138] imx6q-pcie 1ffc000.pcie: host bridge /soc/pcie@1ffc000 ranges:
[    0.256307] imx6q-pcie 1ffc000.pcie:       IO 0x0001f80000..0x0001f8ffff -> 0x0000000000
[    0.256339] imx6q-pcie 1ffc000.pcie:      MEM 0x0001000000..0x0001efffff -> 0x0001000000
[    0.256434] imx6q-pcie 1ffc000.pcie: config reg[1] 0x01f00000 == cpu 0x01f00000
[    0.458388] imx6q-pcie 1ffc000.pcie: iATU: unroll F, 4 ob, 4 ib, align 64K, limit 4G
[    0.458492] imx6q-pcie 1ffc000.pcie: Link: Only Gen1 is enabled
[    0.555294] imx6q-pcie 1ffc000.pcie: PCIe Gen.1 x1 link up
[    0.555783] imx6q-pcie 1ffc000.pcie: PCI host bridge to bus 0000:00
...

The following endpoint devices also yielded the same results.
root@imx6qpdlsolox:~# lspci
00:00.0 PCI bridge: Synopsys, Inc. DWC_usb3 / PCIe bridge (rev 01)
01:00.0 Network controller: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) (rev 01)
root@imx6qpdlsolox:~# uname -a
Linux imx6qpdlsolox 7.2.0-rc7 #30 SMP Tue Aug 11 00:21:26 UTC 2026 armv7l GNU/Linux
...

root@imx6qpdlsolox:~# lspci
00:00.0 PCI bridge: Synopsys, Inc. DWC_usb3 / PCIe bridge (rev 01)
01:00.0 USB controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 04)
root@imx6qpdlsolox:~# uname -a
Linux imx6qpdlsolox 7.2.0-rc7 #30 SMP Tue Aug 11 00:21:26 UTC 2026 armv7l GNU/Linux

Could you provide more details of your hardware setup (board, connected
devices, PERST# present or not)?
This may help us identify if there's a specific scenario that triggers the
regression you're experiencing.

Best Regards
Richard Zhu
> 
> Link:
> https://lore.kernel.org/all/bl7i3obu2clzsgeoct2a4mtfhv6typcjdqmgneropf3hp
> gwve6@n2m5uhlduw57/T/#u