Re: [PATCH v2 1/2] PCI/ASPM: Override the ASPM and Clock PM states set by BIOS for devicetree platforms

[Manivannan Sadhasivam]

On Fri, Mar 06, 2026 at 04:03:35PM +0000, Jon Hunter wrote:
> 
> On 03/03/2026 16:17, Manivannan Sadhasivam wrote:
> 
> ...
> 
> > > For Tegra, we enter a deep low power state known as SC7 on suspend which
> > > does involve firmware. Nonetheless I tried for fun, but this breaks suspend
> > > completely.
> > > 
> > 
> > Ah, this explains the problem. We also have a similar problem on our Qcom Auto
> > boards where the firmware completely shuts down the SoC and puts the DRAM in
> > self refresh mode. So NVMe driver never resumes properly. We tried multiple ways
> > to address this issue in the NVMe driver, but the NVMe maintainers rejected
> > every single one of them and asking for some API in the PCI or PM core to tell
> > the NVMe driver when to shutdown the device during suspend. But this turned out
> > to be not so trivial.
> > 
> > Another way to workaround this issue would be by calling
> > pm_set_suspend_via_firmware() from the driver that controls the entity doing
> > power management of the SoC (firmware). In your case, it is
> > drivers/soc/tegra/pmc.c?
> 
> Actually for newer devices it is PSCI and so ...
> 
> > In that case, you can use this patch as a reference:
> > https://lore.kernel.org/all/20251231162126.7728-1-manivannan.sadhasivam@xxxxxxxxxxxxxxxx
> 
> This change fixes the problem as implemented. What is the status of the
> above? Any plans to get this merged?
> 

It didn't get any love so far. It'd help if you can give your tags to that
patch.

- Mani

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