Re: [PATCH v7 13/13] PCI: tegra194: Free resources during controller deinitialization

[Manikanta Maddireddy]

On 05/03/26 4:13 pm, Manivannan Sadhasivam wrote:
> On Tue, Mar 03, 2026 at 12:24:48PM +0530, Manikanta Maddireddy wrote:
> > From: Vidya Sagar <vidyas@xxxxxxxxxx>
> >
> > Call pci_epc_deinit_notify() during controller deinitialization to free the
> > resources allocated by Endpoint function driver. This is safe to call
> > during PCIe assert sequence because we don't expect Endpoint function
> > driver to touch hardware in deinit function.
>
> Are you sure? The epf-test driver itself touches DBI space during deinit.
>
> - Mani
Ok, I see epf-test is doing clear_bar which access DBI space.
But, I think we should give give a chance to EPF drivers to clean up 
resources and stop using them in PERST# assert. Let me know your inputs 
on this.

- Manikanta

> > Fixes: 40e2125381dc ("PCI: tegra194: Move controller cleanups to pex_ep_event_pex_rst_deassert()")
> > Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> > Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> > Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> > Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>
> > ---
> > Changes V5 -> V7: None
> > Changes V4 -> V5: Remove pci_epc_deinit_notify() call from pex_ep_event_pex_rst_deassert()
> > Changes V1 -> V4: None
> >
> >   drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++++-
> >   1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> > index a311c31109e3..b1ae46761915 100644
> > --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> > @@ -1624,12 +1624,16 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
> >   
> >   static void pex_ep_event_pex_rst_assert(struct tegra_pcie_dw *pcie)
> >   {
> > +	struct dw_pcie *pci = &pcie->pci;
> > +	struct dw_pcie_ep *ep = &pci->ep;
> >   	u32 val;
> >   	int ret;
> >   
> >   	if (pcie->ep_state == EP_STATE_DISABLED)
> >   		return;
> >   
> > +	pci_epc_deinit_notify(ep->epc);
> > +
> >   	ret = readl_poll_timeout(pcie->appl_base + APPL_DEBUG, val,
> >   		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_QUIET) ||
> >   		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_ACT) ||
> > @@ -1796,7 +1800,6 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
> >   	reset_control_deassert(pcie->core_rst);
> >   
> >   	/* Perform cleanup that requires refclk and core reset deasserted */
> > -	pci_epc_deinit_notify(pcie->pci.ep.epc);
> >   	dw_pcie_ep_cleanup(&pcie->pci.ep);
> >   
> >   	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
> > --
> > 2.34.1

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nvpublic