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

[Jon Hunter <jonathanh@nvidia.com>]

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@oss.qualcomm.com

This change fixes the problem as implemented. What is the status of the 
above? Any plans to get this merged?

Jon

-- 
nvpublic