Re: [PATCH v4 1/1] PCI: qcom: Add support for system suspend and resume

[Johan Hovold]

On Mon, Apr 03, 2023 at 09:19:22PM +0530, Manivannan Sadhasivam wrote:
> During the system suspend, vote for minimal interconnect bandwidth (1KiB)
> to keep the interconnect path active for config access and also turn OFF
> the resources like clock and PHY if there are no active devices connected
> to the controller. For the controllers with active devices, the resources
> are kept ON as removing the resources will trigger access violation during
> the late end of suspend cycle as kernel tries to access the config space of
> PCIe devices to mask the MSIs.
> 
> Also, it is not desirable to put the link into L2/L3 state as that
> implies VDD supply will be removed and the devices may go into powerdown
> state. This will affect the lifetime of storage devices like NVMe.
> 
> And finally, during resume, turn ON the resources if the controller was
> truly suspended (resources OFF) and update the interconnect bandwidth
> based on PCIe Gen speed.
> 
> Suggested-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> Acked-by: Dhruva Gole <d-gole@xxxxxx>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>

> +	/*
> +	 * Set minimum bandwidth required to keep data path functional during
> +	 * suspend

Nit: For some reason you dropped the full stop ('.') here in v4 I
noticed when comparing the diff.

> +	 */

Looks good to me now otherwise:

Reviewed-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
Tested-by: Johan Hovold <johan+linaro@xxxxxxxxxx>

Johan