Re: [PATCH v2 1/2] PCI: dwc: Add .post_deinit counterpart to endpoint .pre_init callback

[Koichiro Den]

On Thu, Aug 20, 2026 at 05:57:55AM +0200, Marek Vasut wrote:
> In case the .pre_init() callback fails, it is mandatory to correctly

I think this should be "If .pre_init() succeeds but subsequent initialization
fails,". Otherwise LGTM.
I did some quick tests on an S4 Spider, covering the normal path and several
injected failure paths. I don't have V4H hardware, though.
Please feel free to pick up either or both tags if that helps.

Reviewed-by: Koichiro Den <den@xxxxxxxxxxxxx>
Tested-by: Koichiro Den <den@xxxxxxxxxxxxx>

Best regards,
Koichiro

> undo the hardware configuration which the .pre_init() callback did.
> Intrododuce .post_deinit() callback to do exactly that, undo what
> the .pre_init() callback did. Usually, that means stop the clock,
> assert reset, and possibly program some registers to quiescense the
> hardware. Invoke the .post_deinit() callback in dw_pcie_ep_deinit()
> to retain functional symmetry.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
> ---
> Cc: "Krzysztof Wilczyński" <kwilczynski@xxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Cc: Koichiro Den <den@xxxxxxxxxxxxx>
> Cc: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
> Cc: Magnus Damm <magnus.damm@xxxxxxxxx>
> Cc: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
> ---
> V2: New patch
> ---
>  drivers/pci/controller/dwc/pcie-designware-ep.c | 8 +++++++-
>  drivers/pci/controller/dwc/pcie-designware.h    | 1 +
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index de8ee3db43601..1a3491b5003ec 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -1194,6 +1194,9 @@ void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
>  			      epc->mem->window.page_size);
>  
>  	pci_epc_mem_exit(epc);
> +
> +	if (ep->ops->post_deinit)
> +		ep->ops->post_deinit(ep);
>  }
>  EXPORT_SYMBOL_GPL(dw_pcie_ep_deinit);
>  
> @@ -1553,7 +1556,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>  			       ep->page_size);
>  	if (ret < 0) {
>  		dev_err(dev, "Failed to initialize address space\n");
> -		return ret;
> +		goto err_deinit;
>  	}
>  
>  	ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
> @@ -1568,6 +1571,9 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>  
>  err_exit_epc_mem:
>  	pci_epc_mem_exit(epc);
> +err_deinit:
> +	if (ep->ops->post_deinit)
> +		ep->ops->post_deinit(ep);
>  
>  	return ret;
>  }
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 0735ae9409240..a53ac27cd2447 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -475,6 +475,7 @@ struct dw_pcie_rp {
>  
>  struct dw_pcie_ep_ops {
>  	int	(*pre_init)(struct dw_pcie_ep *ep);
> +	void	(*post_deinit)(struct dw_pcie_ep *ep);
>  	int	(*init)(struct dw_pcie_ep *ep);
>  	int	(*raise_irq)(struct dw_pcie_ep *ep, u8 func_no,
>  			     unsigned int type, u16 interrupt_num);
> -- 
> 2.53.0
>