[PATCH 0/6] PCI: dwc: Revert Link Up IRQ support

[Manivannan Sadhasivam]

On Wed, Nov 26, 2025 at 10:30:06PM +0900, FUKAUMI Naoki wrote:
> Hi Niklas,
> 
> I apologize for the delayed response.
> 
> On 11/24/25 23:02, Niklas Cassel wrote:
> > On Mon, Nov 24, 2025 at 06:07:44PM +0530, Manivannan Sadhasivam wrote:
> > > While I suggested to revert the link up IRQ patch for rockchip earlier, I didn't
> > > expect to drop the support for Qcom. The reason is, on Qcom SoCs, we have not
> > > seen a case where people connect a random PCIe switch and saw failures. Most of
> > > the Qcom usecases were around the M.2 and other proprietary connectors. There is
> > > only one in-house PCIe switch that is being actively used in our products, but
> > > so far, none of the bootloaders have turned them ON before kernel booting. So
> > > kernel relies on the newly merged pwrctrl driver to do the job. Even though it
> > > also suffers from the same resource allocation issue, this series won't help in
> > > any way as pwrctrl core performs rescan after the switch power ON, and by that
> > > time, it will be very late anyway.
> > > 
> > > So I'm happy to take the rockhip patches from this series as they fix the real
> > > issue that people have reported. But once the pwrctrl rework series gets merged,
> > > and the rockchip drivers support them, we can bring back the reverted changes.
> > 
> > FUKAUMI Naoki, just to confirm:
> > 
> > Neither my suggested approach:
> > https://lore.kernel.org/linux-pci/aRHdeVCY3rRmxe80@ryzen/
> > 
> > nor Shawn's suggested approach:
> > https://lore.kernel.org/linux-pci/dc932773-af5b-4af7-a0d0-8cc72dfbd3c7@rock-chips.com/
> > 
> > worked for you?
> 
> Yes, I re-tested the two methods mentioned above, separately, on v6.18-rc7,
> but neither of them resolved the issue in my environment (ROCK 5C +
> ASM2806).
> 
> > If so, I don't see many alternative but for Mani to apply patch 1 and
> > patch 2 from this series.
> 
> I believe applying patch 1 and patch 2 should be sufficient.
> 
> ----
> 
> Incidentally, (probably) while applying patch 1 and patch 2, I have
> encountered the following issue several times:
>

Do you see the below issue *after* applying the patches? I don't know how to
interpret "while applying".
 
> [    1.709614] pcieport 0004:41:00.0: of_irq_parse_pci: failed with rc=134
> [    1.710208] pcieport 0004:41:00.0: Unable to change power state from
> D3cold to D0, device inaccessible
> 

Looks like the device was seen during bus scan, but then it went down
afterwards.

- Mani

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