Re: [PATCH v4 02/18] PCI: dwc: Factor out the PORT_LINK_DEBUG1 link-up check

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

在 2026/10/15 星期四 11:30, Koichiro Den 写道:
> dw_pcie_link_up() reads PORT_LINK_DEBUG1 when the glue driver provides
> no .link_up() callback. A callback that needs a platform-specific check
> on top of that register would have to duplicate the register read.
> 
> Factor the check out into dw_pcie_link_up_debug_check() and export it
> for modular glue drivers. pcie-rcar-gen4 will be the first user: its APP
> link-up events remain latched after the link goes down, so it has to
> combine them with the live PORT_LINK_DEBUG1 state.
> 
> No functional change.
> 

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

> Suggested-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---
> Changes since v3:
>    - No changes.
> 
>   drivers/pci/controller/dwc/pcie-designware.c | 15 +++++++++++----
>   drivers/pci/controller/dwc/pcie-designware.h |  1 +
>   2 files changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index c726aa71c830..49a9ba910ba8 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -817,17 +817,24 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci)
>   }
>   EXPORT_SYMBOL_GPL(dw_pcie_wait_for_link);
>   
> -bool dw_pcie_link_up(struct dw_pcie *pci)
> +/* Link state from PORT_LINK_DEBUG1: up and not in training */
> +bool dw_pcie_link_up_debug_check(struct dw_pcie *pci)
>   {
>   	u32 val;
>   
> -	if (pci->ops && pci->ops->link_up)
> -		return pci->ops->link_up(pci);
> -
>   	val = dw_pcie_readl_dbi(pci, PORT_LINK_DEBUG1);
>   	return ((val & PORT_LINK_DEBUG1_LINK_UP) &&
>   		(!(val & PORT_LINK_DEBUG1_LINK_IN_TRAINING)));
>   }
> +EXPORT_SYMBOL_GPL(dw_pcie_link_up_debug_check);
> +
> +bool dw_pcie_link_up(struct dw_pcie *pci)
> +{
> +	if (pci->ops && pci->ops->link_up)
> +		return pci->ops->link_up(pci);
> +
> +	return dw_pcie_link_up_debug_check(pci);
> +}
>   EXPORT_SYMBOL_GPL(dw_pcie_link_up);
>   
>   void dw_pcie_upconfig_setup(struct dw_pcie *pci)
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 419932488280..2ce61709b58c 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -618,6 +618,7 @@ int dw_pcie_write(void __iomem *addr, int size, u32 val);
>   u32 dw_pcie_read_dbi(struct dw_pcie *pci, u32 reg, size_t size);
>   void dw_pcie_write_dbi(struct dw_pcie *pci, u32 reg, size_t size, u32 val);
>   void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val);
> +bool dw_pcie_link_up_debug_check(struct dw_pcie *pci);
>   bool dw_pcie_link_up(struct dw_pcie *pci);
>   void dw_pcie_upconfig_setup(struct dw_pcie *pci);
>   int dw_pcie_wait_for_link(struct dw_pcie *pci);