[PATCH v4 0/1] net: ravb: fixes for the ravb driver

[PATCH v4 0/1] net: ravb: fixes for the ravb driver

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Hi,

Series adds one fix for the ravb driver to wait for the operating
mode to be applied by hardware before proceeding.

Thank you,
Claudiu Beznea

Change in v4:
- rephrase a paragraph from patch description
- added a comment in ravb_set_opmode()
- collected Rb tag

Changes in v3:
- s/csr_opmode/csr_ops in ravb_set_opmode()
- mask opmode with CCC_OPC when retrieveing csr_ops
- in ravb_set_opmode() updated modify mask passed to ravb_modify() to
  include GAC and CSEL bits if these are part of opmode
- s/failed to switch device to config mode/failed to switch device to
  requested mode/ in ravb_set_opmode()
- s/operation/operating in the title of patch 1/1

Changes in v2:
- dropped patch 2/2 from v1 ("net: ravb: Check that GTI loading request is
  done")
- kept a single "Fixes" entry in commit description
- updated commit description for patch 1/1
- introduce ravb_set_opmode() that does all the necessities for
  setting the operating mode (set DMA.CCC and wait for CSR.OPS) and call it
  where needed; this should comply with all the HW manuals requirements as
  different manual variants specify different modes need to be checked in
  CSR.OPS when setting DMA.CCC.

Claudiu Beznea (1):
  net: ravb: Wait for operating mode to be applied

 drivers/net/ethernet/renesas/ravb_main.c | 65 +++++++++++++++---------
 1 file changed, 42 insertions(+), 23 deletions(-)

-- 
2.39.2

[PATCH v4 1/1] net: ravb: Wait for operating mode to be applied

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

CSR.OPS bits specify the current operating mode and (according to
documentation) they are updated by HW when the operating mode change
request is processed. To comply with this check CSR.OPS before proceeding.

Commit introduces ravb_set_opmode() that does all the necessities for
setting the operating mode (set CCC.OPC (and CCC.GAC, CCC.CSEL, if any) and
wait for CSR.OPS) and call it where needed. This should comply with all the
HW manuals requirements as different manual variants specify that different
modes need to be checked in CSR.OPS when setting CCC.OPC.

If gPTP active in config mode is supported and it needs to be enabled, the
CCC.GAC and CCC.CSEL needs to be configured along with CCC.OPC in the same
write access. For this, ravb_set_opmode() allows passing GAC and CSEL as
part of opmode and the function updates accordingly CCC register.

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
---
 drivers/net/ethernet/renesas/ravb_main.c | 65 +++++++++++++++---------
 1 file changed, 42 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 664eda4b5a11..8649b3e90edb 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -66,16 +66,27 @@ int ravb_wait(struct net_device *ndev, enum ravb_reg reg, u32 mask, u32 value)
 	return -ETIMEDOUT;
 }
 
-static int ravb_config(struct net_device *ndev)
+static int ravb_set_opmode(struct net_device *ndev, u32 opmode)
 {
+	u32 csr_ops = 1U << (opmode & CCC_OPC);
+	u32 ccc_mask = CCC_OPC;
 	int error;
 
-	/* Set config mode */
-	ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG);
-	/* Check if the operating mode is changed to the config mode */
-	error = ravb_wait(ndev, CSR, CSR_OPS, CSR_OPS_CONFIG);
-	if (error)
-		netdev_err(ndev, "failed to switch device to config mode\n");
+	/* If gPTP active in config mode is supported it needs to be configured
+	 * along with CSEL and operating mode in the same access. This is a
+	 * hardware limitation.
+	 */
+	if (opmode & CCC_GAC)
+		ccc_mask |= CCC_GAC | CCC_CSEL;
+
+	/* Set operating mode */
+	ravb_modify(ndev, CCC, ccc_mask, opmode);
+	/* Check if the operating mode is changed to the requested one */
+	error = ravb_wait(ndev, CSR, CSR_OPS, csr_ops);
+	if (error) {
+		netdev_err(ndev, "failed to switch device to requested mode (%u)\n",
+			   opmode & CCC_OPC);
+	}
 
 	return error;
 }
@@ -673,7 +684,7 @@ static int ravb_dmac_init(struct net_device *ndev)
 	int error;
 
 	/* Set CONFIG mode */
-	error = ravb_config(ndev);
+	error = ravb_set_opmode(ndev, CCC_OPC_CONFIG);
 	if (error)
 		return error;
 
@@ -682,9 +693,7 @@ static int ravb_dmac_init(struct net_device *ndev)
 		return error;
 
 	/* Setting the control will start the AVB-DMAC process. */
-	ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_OPERATION);
-
-	return 0;
+	return ravb_set_opmode(ndev, CCC_OPC_OPERATION);
 }
 
 static void ravb_get_tx_tstamp(struct net_device *ndev)
@@ -1046,7 +1055,7 @@ static int ravb_stop_dma(struct net_device *ndev)
 		return error;
 
 	/* Stop AVB-DMAC process */
-	return ravb_config(ndev);
+	return ravb_set_opmode(ndev, CCC_OPC_CONFIG);
 }
 
 /* E-MAC interrupt handler */
@@ -2560,21 +2569,25 @@ static int ravb_set_gti(struct net_device *ndev)
 	return 0;
 }
 
-static void ravb_set_config_mode(struct net_device *ndev)
+static int ravb_set_config_mode(struct net_device *ndev)
 {
 	struct ravb_private *priv = netdev_priv(ndev);
 	const struct ravb_hw_info *info = priv->info;
+	int error;
 
 	if (info->gptp) {
-		ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG);
+		error = ravb_set_opmode(ndev, CCC_OPC_CONFIG);
+		if (error)
+			return error;
 		/* Set CSEL value */
 		ravb_modify(ndev, CCC, CCC_CSEL, CCC_CSEL_HPB);
 	} else if (info->ccc_gac) {
-		ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG |
-			    CCC_GAC | CCC_CSEL_HPB);
+		error = ravb_set_opmode(ndev, CCC_OPC_CONFIG | CCC_GAC | CCC_CSEL_HPB);
 	} else {
-		ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG);
+		error = ravb_set_opmode(ndev, CCC_OPC_CONFIG);
 	}
+
+	return error;
 }
 
 /* Set tx and rx clock internal delay modes */
@@ -2794,7 +2807,9 @@ static int ravb_probe(struct platform_device *pdev)
 	ndev->ethtool_ops = &ravb_ethtool_ops;
 
 	/* Set AVB config mode */
-	ravb_set_config_mode(ndev);
+	error = ravb_set_config_mode(ndev);
+	if (error)
+		goto out_disable_gptp_clk;
 
 	if (info->gptp || info->ccc_gac) {
 		/* Set GTI value */
@@ -2917,8 +2932,7 @@ static void ravb_remove(struct platform_device *pdev)
 	dma_free_coherent(ndev->dev.parent, priv->desc_bat_size, priv->desc_bat,
 			  priv->desc_bat_dma);
 
-	/* Set reset mode */
-	ravb_write(ndev, CCC_OPC_RESET, CCC);
+	ravb_set_opmode(ndev, CCC_OPC_RESET);
 
 	clk_disable_unprepare(priv->gptp_clk);
 	clk_disable_unprepare(priv->refclk);
@@ -3000,8 +3014,11 @@ static int __maybe_unused ravb_resume(struct device *dev)
 	int ret = 0;
 
 	/* If WoL is enabled set reset mode to rearm the WoL logic */
-	if (priv->wol_enabled)
-		ravb_write(ndev, CCC_OPC_RESET, CCC);
+	if (priv->wol_enabled) {
+		ret = ravb_set_opmode(ndev, CCC_OPC_RESET);
+		if (ret)
+			return ret;
+	}
 
 	/* All register have been reset to default values.
 	 * Restore all registers which where setup at probe time and
@@ -3009,7 +3026,9 @@ static int __maybe_unused ravb_resume(struct device *dev)
 	 */
 
 	/* Set AVB config mode */
-	ravb_set_config_mode(ndev);
+	ret = ravb_set_config_mode(ndev);
+	if (ret)
+		return ret;
 
 	if (info->gptp || info->ccc_gac) {
 		/* Set GTI value */
-- 
2.39.2

Re: [PATCH v4 0/1] net: ravb: fixes for the ravb driver

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Wed,  3 Jan 2024 10:13:52 +0200 you wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> Hi,
> 
> Series adds one fix for the ravb driver to wait for the operating
> mode to be applied by hardware before proceeding.
> 
> [...]

Here is the summary with links:
  - [v4,1/1] net: ravb: Wait for operating mode to be applied
    https://git.kernel.org/netdev/net/c/9039cd4c6163

You are awesome, thank you!
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