Re: [PATCH v8 09/14] PCI: tegra194: Allow system suspend when the Endpoint link is not up

[Bjorn Helgaas]

On Wed, Apr 08, 2026 at 03:59:59PM -0500, Bjorn Helgaas wrote:
> On Wed, Mar 25, 2026 at 12:37:50AM +0530, Manikanta Maddireddy wrote:
> > From: Vidya Sagar <vidyas@xxxxxxxxxx>
> > 
> > Host software initiates the L2 sequence. PCIe link is kept in L2 state
> > during suspend. If Endpoint mode is enabled and the link is up, the
> > software cannot proceed with suspend. However, when the PCIe Endpoint
> > driver is probed, but the PCIe link is not up, Tegra can go into suspend
> > state. So, allow system to suspend in this case.
> 
> > +static int tegra_pcie_dw_suspend(struct device *dev)
> >  {
> >  	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
> > -	u32 val;
> >  
> >  	if (pcie->of_data->mode == DW_PCIE_EP_TYPE) {
> > -		dev_err(dev, "Failed to Suspend as Tegra PCIe is in EP mode\n"); > -		return -EPERM;
> > +		if (pcie->ep_state == EP_STATE_ENABLED) {
> > +			dev_err(dev, "Tegra PCIe is in EP mode, suspend not allowed\n");
> 
> Should this message say something about endpoint suspend not being
> allowed because the link is up?  IIUC, the endpoint *can* suspend if
> the link is down.

Oh, and I forgot: the subject line says "allow *system* suspend", but
it looks like this patch is concerned with *endpoint* suspend.

I assume that whatever an endpoint does, it can't prevent the host
from suspending?  I guess I'm just confused about the usage of "system
suspend" in the subject line and commit message -- does "system" refer
to the host or the endpoint?