diff mbox series

[v16,10/22] PCI: dwc: Modify PCIE_PORT_LINK_CONTROL handling

Message ID 20230510062234.201499-11-yoshihiro.shimoda.uh@renesas.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series PCI: rcar-gen4: Add R-Car Gen4 PCIe support | expand

Commit Message

Yoshihiro Shimoda May 10, 2023, 6:22 a.m. UTC 
To improve code readability, modify PCIE_PORT_LINK_CONTROL handling.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/pci/controller/dwc/pcie-designware.c | 40 +++++++-------------
 1 file changed, 13 insertions(+), 27 deletions(-)

Comments

Serge Semin June 5, 2023, 10:53 a.m. UTC | #1 
On Wed, May 10, 2023 at 03:22:22PM +0900, Yoshihiro Shimoda wrote:
> To improve code readability, modify PCIE_PORT_LINK_CONTROL handling.

So basically you are doing the same update as in the Patch 9:
detaching the already implemented link width setups into a separate
method. Why do you split them up into the incremental updates? Just
squash this patch into the patch 9. The resultant patch would be an
atomic update and a preparation before adding the PCI_EXP_LNKCAP field
update. The later would lead to the fully coherent maximum link width
setup method in accordance with the DW PCIe hardware manual.

-Serge(y)

> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>  drivers/pci/controller/dwc/pcie-designware.c | 40 +++++++-------------
>  1 file changed, 13 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index 68aefbbcd68c..5dc423dd2f21 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -721,28 +721,40 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
>  
>  static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
>  {
> -	u32 lwsc;
> +	u32 lwsc, plc;
>  
>  	if (!num_lanes)
>  		return;
>  
> +	/* Set the number of lanes */
> +	plc = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
> +	plc &= ~PORT_LINK_MODE_MASK;
> +
>  	/* Set link width speed control register */
>  	lwsc = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
>  	lwsc &= ~PORT_LOGIC_LINK_WIDTH_MASK;
>  	switch (num_lanes) {
>  	case 1:
> +		plc |= PORT_LINK_MODE_1_LANES;
>  		lwsc |= PORT_LOGIC_LINK_WIDTH_1_LANES;
>  		break;
>  	case 2:
> +		plc |= PORT_LINK_MODE_2_LANES;
>  		lwsc |= PORT_LOGIC_LINK_WIDTH_2_LANES;
>  		break;
>  	case 4:
> +		plc |= PORT_LINK_MODE_4_LANES;
>  		lwsc |= PORT_LOGIC_LINK_WIDTH_4_LANES;
>  		break;
>  	case 8:
> +		plc |= PORT_LINK_MODE_8_LANES;
>  		lwsc |= PORT_LOGIC_LINK_WIDTH_8_LANES;
>  		break;
> +	default:
> +		dev_err(pci->dev, "num-lanes %u: invalid value\n", num_lanes);
> +		return;
>  	}
> +	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc);
>  	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc);
>  }
>  
> @@ -1027,31 +1039,5 @@ void dw_pcie_setup(struct dw_pcie *pci)
>  	val |= PORT_LINK_DLL_LINK_EN;
>  	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
>  
> -	if (!pci->num_lanes) {
> -		dev_dbg(pci->dev, "Using h/w default number of lanes\n");
> -		return;
> -	}
> -
> -	/* Set the number of lanes */
> -	val &= ~PORT_LINK_MODE_MASK;
> -	switch (pci->num_lanes) {
> -	case 1:
> -		val |= PORT_LINK_MODE_1_LANES;
> -		break;
> -	case 2:
> -		val |= PORT_LINK_MODE_2_LANES;
> -		break;
> -	case 4:
> -		val |= PORT_LINK_MODE_4_LANES;
> -		break;
> -	case 8:
> -		val |= PORT_LINK_MODE_8_LANES;
> -		break;
> -	default:
> -		dev_err(pci->dev, "num-lanes %u: invalid value\n", pci->num_lanes);
> -		return;
> -	}
> -	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
> -
>  	dw_pcie_link_set_max_link_width(pci, pci->num_lanes);
>  }
> -- 
> 2.25.1
>
Yoshihiro Shimoda June 6, 2023, 9:28 a.m. UTC | #2 
Hello Serge,

> From: Serge Semin, Sent: Monday, June 5, 2023 7:53 PM
> 
> On Wed, May 10, 2023 at 03:22:22PM +0900, Yoshihiro Shimoda wrote:
> > To improve code readability, modify PCIE_PORT_LINK_CONTROL handling.
> 
> So basically you are doing the same update as in the Patch 9:
> detaching the already implemented link width setups into a separate
> method. Why do you split them up into the incremental updates?

I thought that splitting them was review-friendly. But, it's wrong...

> Just
> squash this patch into the patch 9. The resultant patch would be an
> atomic update and a preparation before adding the PCI_EXP_LNKCAP field
> update. The later would lead to the fully coherent maximum link width
> setup method in accordance with the DW PCIe hardware manual.

I got it.

Best regards,
Yoshihiro Shimoda

> -Serge(y)
> 
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > ---
> >  drivers/pci/controller/dwc/pcie-designware.c | 40 +++++++-------------
> >  1 file changed, 13 insertions(+), 27 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> > index 68aefbbcd68c..5dc423dd2f21 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -721,28 +721,40 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
> >
> >  static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
> >  {
> > -	u32 lwsc;
> > +	u32 lwsc, plc;
> >
> >  	if (!num_lanes)
> >  		return;
> >
> > +	/* Set the number of lanes */
> > +	plc = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
> > +	plc &= ~PORT_LINK_MODE_MASK;
> > +
> >  	/* Set link width speed control register */
> >  	lwsc = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
> >  	lwsc &= ~PORT_LOGIC_LINK_WIDTH_MASK;
> >  	switch (num_lanes) {
> >  	case 1:
> > +		plc |= PORT_LINK_MODE_1_LANES;
> >  		lwsc |= PORT_LOGIC_LINK_WIDTH_1_LANES;
> >  		break;
> >  	case 2:
> > +		plc |= PORT_LINK_MODE_2_LANES;
> >  		lwsc |= PORT_LOGIC_LINK_WIDTH_2_LANES;
> >  		break;
> >  	case 4:
> > +		plc |= PORT_LINK_MODE_4_LANES;
> >  		lwsc |= PORT_LOGIC_LINK_WIDTH_4_LANES;
> >  		break;
> >  	case 8:
> > +		plc |= PORT_LINK_MODE_8_LANES;
> >  		lwsc |= PORT_LOGIC_LINK_WIDTH_8_LANES;
> >  		break;
> > +	default:
> > +		dev_err(pci->dev, "num-lanes %u: invalid value\n", num_lanes);
> > +		return;
> >  	}
> > +	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc);
> >  	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc);
> >  }
> >
> > @@ -1027,31 +1039,5 @@ void dw_pcie_setup(struct dw_pcie *pci)
> >  	val |= PORT_LINK_DLL_LINK_EN;
> >  	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
> >
> > -	if (!pci->num_lanes) {
> > -		dev_dbg(pci->dev, "Using h/w default number of lanes\n");
> > -		return;
> > -	}
> > -
> > -	/* Set the number of lanes */
> > -	val &= ~PORT_LINK_MODE_MASK;
> > -	switch (pci->num_lanes) {
> > -	case 1:
> > -		val |= PORT_LINK_MODE_1_LANES;
> > -		break;
> > -	case 2:
> > -		val |= PORT_LINK_MODE_2_LANES;
> > -		break;
> > -	case 4:
> > -		val |= PORT_LINK_MODE_4_LANES;
> > -		break;
> > -	case 8:
> > -		val |= PORT_LINK_MODE_8_LANES;
> > -		break;
> > -	default:
> > -		dev_err(pci->dev, "num-lanes %u: invalid value\n", pci->num_lanes);
> > -		return;
> > -	}
> > -	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
> > -
> >  	dw_pcie_link_set_max_link_width(pci, pci->num_lanes);
> >  }
> > --
> > 2.25.1
> >
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 68aefbbcd68c..5dc423dd2f21 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -721,28 +721,40 @@  static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
 
 static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
 {
-	u32 lwsc;
+	u32 lwsc, plc;
 
 	if (!num_lanes)
 		return;
 
+	/* Set the number of lanes */
+	plc = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
+	plc &= ~PORT_LINK_MODE_MASK;
+
 	/* Set link width speed control register */
 	lwsc = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
 	lwsc &= ~PORT_LOGIC_LINK_WIDTH_MASK;
 	switch (num_lanes) {
 	case 1:
+		plc |= PORT_LINK_MODE_1_LANES;
 		lwsc |= PORT_LOGIC_LINK_WIDTH_1_LANES;
 		break;
 	case 2:
+		plc |= PORT_LINK_MODE_2_LANES;
 		lwsc |= PORT_LOGIC_LINK_WIDTH_2_LANES;
 		break;
 	case 4:
+		plc |= PORT_LINK_MODE_4_LANES;
 		lwsc |= PORT_LOGIC_LINK_WIDTH_4_LANES;
 		break;
 	case 8:
+		plc |= PORT_LINK_MODE_8_LANES;
 		lwsc |= PORT_LOGIC_LINK_WIDTH_8_LANES;
 		break;
+	default:
+		dev_err(pci->dev, "num-lanes %u: invalid value\n", num_lanes);
+		return;
 	}
+	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc);
 	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc);
 }
 
@@ -1027,31 +1039,5 @@  void dw_pcie_setup(struct dw_pcie *pci)
 	val |= PORT_LINK_DLL_LINK_EN;
 	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
 
-	if (!pci->num_lanes) {
-		dev_dbg(pci->dev, "Using h/w default number of lanes\n");
-		return;
-	}
-
-	/* Set the number of lanes */
-	val &= ~PORT_LINK_MODE_MASK;
-	switch (pci->num_lanes) {
-	case 1:
-		val |= PORT_LINK_MODE_1_LANES;
-		break;
-	case 2:
-		val |= PORT_LINK_MODE_2_LANES;
-		break;
-	case 4:
-		val |= PORT_LINK_MODE_4_LANES;
-		break;
-	case 8:
-		val |= PORT_LINK_MODE_8_LANES;
-		break;
-	default:
-		dev_err(pci->dev, "num-lanes %u: invalid value\n", pci->num_lanes);
-		return;
-	}
-	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
-
 	dw_pcie_link_set_max_link_width(pci, pci->num_lanes);
 }