Re: [PATCH net-next 1/2] ravb: Add tx and rx clock internal delays mode of APSR

On Fri, Jan 27, 2017 at 04:00:27PM +0300, Sergei Shtylyov wrote:

On 01/27/2017 02:04 PM, Simon Horman wrote:

quoted

From: Kazuya Mizuguchi <redacted>

This patch enables tx and rx clock internal delay modes (TDM and RDM).

This is to address a failure in the case of 1Gbps communication using the
by salvator-x board with the KSZ9031RNX phy. This has been reported to
occur with both the r8a7795 (H3) and r8a7796 (M3-W) SoCs.

With this change APSR internal delay modes are enabled for
"rgmii-id", "rgmii-rxid" and "rgmii-txid" phy modes as follows:

phy mode   | ASPR delay mode
-----------+----------------
rgmii-id   | TDM and RDM
rgmii-rxid | RDM
rgmii-txid | TDM

Signed-off-by: Kazuya Mizuguchi <redacted>
Signed-off-by: Simon Horman <redacted>

---
v1 [Simon Horman]
- Combined patches
- Reworded changelog

v0 [Kazuya Mizuguchi]

[...]

quoted

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 89ac1e3f6175..9fb4c04c5885 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c

@@ -1904,6 +1904,29 @@ static void ravb_set_config_mode(struct net_device *ndev)

	}
}

+static void ravb_set_delay_mode(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	if (priv->chip_id != RCAR_GEN2) {
+		switch (priv->phy_interface) {
+		case PHY_INTERFACE_MODE_RGMII_ID:
+			ravb_modify(ndev, APSR, APSR_DM, APSR_DM_RDM |
+				   APSR_DM_TDM);
+			break;
+		case PHY_INTERFACE_MODE_RGMII_RXID:
+			ravb_modify(ndev, APSR, APSR_DM, APSR_DM_RDM);
+			break;
+		case PHY_INTERFACE_MODE_RGMII_TXID:
+			ravb_modify(ndev, APSR, APSR_DM, APSR_DM_TDM);
+			break;
+		default:
+			ravb_modify(ndev, APSR, APSR_DM, 0);
+			break;
+		}
+	}
+}
+
static int ravb_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;

@@ -2016,6 +2039,9 @@ static int ravb_probe(struct platform_device *pdev)

	/* Request GTI loading */
	ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);

+	/* Set APSR */
+	ravb_set_delay_mode(ndev);
+
	/* Allocate descriptor base address table */
	priv->desc_bat_size = sizeof(struct ravb_desc) * DBAT_ENTRY_NUM;
	priv->desc_bat = dma_alloc_coherent(ndev->dev.parent, priv->desc_bat_size,

@@ -2152,6 +2178,9 @@ static int __maybe_unused ravb_resume(struct device *dev)

	/* Request GTI loading */
	ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);

+	/* Set APSR */
+	ravb_set_delay_mode(ndev);
+

   So far the pattern was to first check if gen != 2, then calling a gen3
specific function. I'd like to keep it, rather than checking in the function
itself.

So you would like something like?

	/* Set APSR */
	if (priv->chip_id != RCAR_GEN2)
		 ravb_set_delay_mode(ndev);

That does not seem better to me but I can make it so if that is your
preference.