Re: [PATCH v4 6/6] PCI: dwc: Skip failure during dw_pcie_resume_noirq() if no device is available

[Shawn Lin <shawn.lin@rock-chips.com>]

在 2026/01/07 星期三 16:11, Manivannan Sadhasivam via B4 Relay 写道:
> From: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
> 
> If there is no device attached to any of the Root Ports available under the
> Root bus before suspend and during resume, then there is no point in
> returning failure.
> 
> So skip returning failure so that the resume succeeds and allow the device
> to get attached later.
> 
> If there was a device before suspend and not available during resume, then
> propagate the error to indicate that the device got removed during suspend.
> 

Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>


> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
> ---
>   drivers/pci/controller/dwc/pcie-designware-host.c | 17 ++++++++++++-----
>   1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index ccde12b85463..c30a2ed324cd 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -20,6 +20,7 @@
>   #include <linux/platform_device.h>
>   
>   #include "../../pci.h"
> +#include "../pci-host-common.h"
>   #include "pcie-designware.h"
>   
>   static struct pci_ops dw_pcie_ops;
> @@ -1227,6 +1228,7 @@ EXPORT_SYMBOL_GPL(dw_pcie_suspend_noirq);
>   
>   int dw_pcie_resume_noirq(struct dw_pcie *pci)
>   {
> +	struct dw_pcie_rp *pp = &pci->pp;
>   	int ret;
>   
>   	if (!pci->suspended)
> @@ -1234,23 +1236,28 @@ int dw_pcie_resume_noirq(struct dw_pcie *pci)
>   
>   	pci->suspended = false;
>   
> -	if (pci->pp.ops->init) {
> -		ret = pci->pp.ops->init(&pci->pp);
> +	if (pp->ops->init) {
> +		ret = pp->ops->init(pp);
>   		if (ret) {
>   			dev_err(pci->dev, "Host init failed: %d\n", ret);
>   			return ret;
>   		}
>   	}
>   
> -	dw_pcie_setup_rc(&pci->pp);
> +	dw_pcie_setup_rc(pp);
>   
>   	ret = dw_pcie_start_link(pci);
>   	if (ret)
>   		return ret;
>   
>   	ret = dw_pcie_wait_for_link(pci);
> -	if (ret)
> -		return ret;
> +	/*
> +	 * Skip failure if there is no device attached to the bus now and before
> +	 * suspend. But the error should be returned if a device was attached
> +	 * before suspend and not available now.
> +	 */
> +	if (ret == -ENODEV && !pci_root_ports_have_device(pp->bridge->bus))
> +		return 0;
>   
>   	return ret;
>   }
>