[PATCH v1] PCI: imx6: Move clock enable after core reset assertion

[Francesco Dolcini]

On Thu, Aug 13, 2026 at 04:29:00PM +0800, hongxing.zhu at oss.nxp.com wrote:
> From: Richard Zhu <hongxing.zhu at nxp.com>
> 
> Commit 610fa91d9863 ("PCI: imx6: Assert PERST# before enabling regulators")
> inadvertently moved clock enablement before core reset assertion, breaking
> PCI device initialization on i.MX6Q Apalis platforms when
> ASM1061/ASM1062 is connected.
> 
> Logs:
> root at apalis-imx6-11486042:~# dmesg | grep pcie
> imx6q-pcie 1ffc000.pcie: host bridge /soc/pcie at 1ffc000 ranges:
> imx6q-pcie 1ffc000.pcie:       IO 0x0001f80000..0x0001f8ffff -> 0x0000000000
> imx6q-pcie 1ffc000.pcie:      MEM 0x0001000000..0x0001efffff -> 0x0001000000
> imx6q-pcie 1ffc000.pcie: config reg[1] 0x01f00000 == cpu 0x01f00000
> imx6q-pcie 1ffc000.pcie: iATU: unroll F, 4 ob, 4 ib, align 64K, limit 4G
> imx6q-pcie 1ffc000.pcie: Link: Only Gen1 is enabled
> imx6q-pcie 1ffc000.pcie: Link failed to come up. LTSSM: POLL_CONFIG
> imx6q-pcie 1ffc000.pcie: probe with driver imx6q-pcie failed with error -110
> 
> To fix this regression, restore the original sequence where clocks are
> enabled after asserting core reset and configuring the controller type.
> 
> Fixes: 610fa91d9863 ("PCI: imx6: Assert PERST# before enabling regulators")
> Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
> Reported-by: Leonardo Costa <leoreis.costa at gmail.com>
> Closes: https://lore.kernel.org/all/bl7i3obu2clzsgeoct2a4mtfhv6typcjdqmgneropf3hpgwve6@n2m5uhlduw57/T/#u
> Reported-by: Franz Schnyder <fra.schnyder at gmail.com>
> Closes: https://lore.kernel.org/all/t65y5d54axtksbfs7r4olcefqhwm6m4dz3njgnrnf7fcotj74i@o7avoznlafbj/
> Cc: stable at vger.kernel.org # 7.1+

7.2+, 7.1 does not have the broken commit

minor: it is not 100% clear if the issue is specific to the ASM1061/ASM1062
device or on the specific power-up sequence (reset vs cold-power-on).

Francesco