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* [PATCH v2 0/6] net: stmmac: make DMA programmable burst length more configurable
@ 2016-12-05  9:10 Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 1/6] net: stmmac: return error if no DMA configuration is found Niklas Cassel
                   ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: Niklas Cassel @ 2016-12-05  9:10 UTC (permalink / raw)
  To: netdev; +Cc: Niklas Cassel, devicetree, linux-kernel, linux-doc

From: Niklas Cassel <niklas.cassel@axis.com>

Make DMA programmable burst length more configurable in the stmmac driver.

This is done by adding support for independent pbl for tx/rx through DT.
More fine grained tuning of pbl is possible thanks to a DT property saying
that we should NOT multiply pbl values by x8/x4 in hardware.

All new DT properties are optional, and created in a way that it will not
affect any existing DT configurations.

Changes since V1:
Created cover-letter.
Rebased patch set against next-20161205, since conflicting patches to
stmmac_platform.c has been merged since V1.


Niklas Cassel (6):
  net: stmmac: return error if no DMA configuration is found
  net: stmmac: simplify the common DMA init API
  net: stmmac: stmmac_platform: fix parsing of DT binding
  net: stmmac: dwmac1000: fix define DMA_BUS_MODE_RPBL_MASK
  net: stmmac: add support for independent DMA pbl for tx/rx
  net: smmac: allow configuring lower pbl values

 Documentation/devicetree/bindings/net/stmmac.txt   |  8 +++++-
 Documentation/networking/stmmac.txt                | 24 ++++++++++++-----
 drivers/net/ethernet/stmicro/stmmac/common.h       |  4 +--
 drivers/net/ethernet/stmicro/stmmac/dwmac1000.h    |  2 +-
 .../net/ethernet/stmicro/stmmac/dwmac1000_dma.c    | 26 ++++++++++---------
 drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c |  7 ++---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c   | 25 ++++++++++--------
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  | 17 ++++++------
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c   |  2 ++
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  | 30 ++++++++++++----------
 include/linux/stmmac.h                             |  3 +++
 11 files changed, 89 insertions(+), 59 deletions(-)

-- 
2.1.4

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v2 1/6] net: stmmac: return error if no DMA configuration is found
  2016-12-05  9:10 [PATCH v2 0/6] net: stmmac: make DMA programmable burst length more configurable Niklas Cassel
@ 2016-12-05  9:10 ` Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 2/6] net: stmmac: simplify the common DMA init API Niklas Cassel
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 6+ messages in thread
From: Niklas Cassel @ 2016-12-05  9:10 UTC (permalink / raw)
  To: Giuseppe Cavallaro, Alexandre Torgue; +Cc: Niklas Cassel, netdev, linux-kernel

From: Niklas Cassel <niklas.cassel@axis.com>

All drivers except pci glue layer calls stmmac_probe_config_dt.
stmmac_probe_config_dt does a kzalloc dma_cfg.

pci glue layer does kzalloc dma_cfg explicitly, so all current
drivers does a kzalloc dma_cfg.

Return an error if no DMA configuration is found, that way
we can assume that the DMA configuration always exists.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 982c95213da4..14366800e5e6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1578,16 +1578,12 @@ static void stmmac_check_ether_addr(struct stmmac_priv *priv)
  */
 static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 {
-	int pbl = DEFAULT_DMA_PBL, fixed_burst = 0, aal = 0;
-	int mixed_burst = 0;
 	int atds = 0;
 	int ret = 0;
 
-	if (priv->plat->dma_cfg) {
-		pbl = priv->plat->dma_cfg->pbl;
-		fixed_burst = priv->plat->dma_cfg->fixed_burst;
-		mixed_burst = priv->plat->dma_cfg->mixed_burst;
-		aal = priv->plat->dma_cfg->aal;
+	if (!priv->plat->dma_cfg) {
+		dev_err(priv->device, "DMA configuration not found\n");
+		return -EINVAL;
 	}
 
 	if (priv->extend_desc && (priv->mode == STMMAC_RING_MODE))
@@ -1599,8 +1595,12 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 		return ret;
 	}
 
-	priv->hw->dma->init(priv->ioaddr, pbl, fixed_burst, mixed_burst,
-			    aal, priv->dma_tx_phy, priv->dma_rx_phy, atds);
+	priv->hw->dma->init(priv->ioaddr,
+			    priv->plat->dma_cfg->pbl,
+			    priv->plat->dma_cfg->fixed_burst,
+			    priv->plat->dma_cfg->mixed_burst,
+			    priv->plat->dma_cfg->aal,
+			    priv->dma_tx_phy, priv->dma_rx_phy, atds);
 
 	if (priv->synopsys_id >= DWMAC_CORE_4_00) {
 		priv->rx_tail_addr = priv->dma_rx_phy +
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v2 2/6] net: stmmac: simplify the common DMA init API
  2016-12-05  9:10 [PATCH v2 0/6] net: stmmac: make DMA programmable burst length more configurable Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 1/6] net: stmmac: return error if no DMA configuration is found Niklas Cassel
@ 2016-12-05  9:10 ` Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 3/6] net: stmmac: stmmac_platform: fix parsing of DT binding Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 4/6] net: stmmac: dwmac1000: fix define DMA_BUS_MODE_RPBL_MASK Niklas Cassel
  3 siblings, 0 replies; 6+ messages in thread
From: Niklas Cassel @ 2016-12-05  9:10 UTC (permalink / raw)
  To: Giuseppe Cavallaro, Alexandre Torgue; +Cc: Niklas Cassel, netdev, linux-kernel

From: Niklas Cassel <niklas.cassel@axis.com>

Use struct stmmac_dma_cfg *dma_cfg as an argument rather
than using all the struct members as individual arguments.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
 drivers/net/ethernet/stmicro/stmmac/common.h        |  4 ++--
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c | 13 +++++++------
 drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c  |  7 ++++---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c    | 14 ++++++++------
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c   |  6 +-----
 5 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 3ced2e1703c1..b13a144f72ad 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -412,8 +412,8 @@ extern const struct stmmac_desc_ops ndesc_ops;
 struct stmmac_dma_ops {
 	/* DMA core initialization */
 	int (*reset)(void __iomem *ioaddr);
-	void (*init)(void __iomem *ioaddr, int pbl, int fb, int mb,
-		     int aal, u32 dma_tx, u32 dma_rx, int atds);
+	void (*init)(void __iomem *ioaddr, struct stmmac_dma_cfg *dma_cfg,
+		     u32 dma_tx, u32 dma_rx, int atds);
 	/* Configure the AXI Bus Mode Register */
 	void (*axi)(void __iomem *ioaddr, struct stmmac_axi *axi);
 	/* Dump DMA registers */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index 990746955216..01d0d0f315e5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -82,8 +82,9 @@ static void dwmac1000_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
 	writel(value, ioaddr + DMA_AXI_BUS_MODE);
 }
 
-static void dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
-			       int aal, u32 dma_tx, u32 dma_rx, int atds)
+static void dwmac1000_dma_init(void __iomem *ioaddr,
+			       struct stmmac_dma_cfg *dma_cfg,
+			       u32 dma_tx, u32 dma_rx, int atds)
 {
 	u32 value = readl(ioaddr + DMA_BUS_MODE);
 
@@ -99,20 +100,20 @@ static void dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
 	 */
 	value |= DMA_BUS_MODE_MAXPBL;
 	value &= ~DMA_BUS_MODE_PBL_MASK;
-	value |= (pbl << DMA_BUS_MODE_PBL_SHIFT);
+	value |= (dma_cfg->pbl << DMA_BUS_MODE_PBL_SHIFT);
 
 	/* Set the Fixed burst mode */
-	if (fb)
+	if (dma_cfg->fixed_burst)
 		value |= DMA_BUS_MODE_FB;
 
 	/* Mixed Burst has no effect when fb is set */
-	if (mb)
+	if (dma_cfg->mixed_burst)
 		value |= DMA_BUS_MODE_MB;
 
 	if (atds)
 		value |= DMA_BUS_MODE_ATDS;
 
-	if (aal)
+	if (dma_cfg->aal)
 		value |= DMA_BUS_MODE_AAL;
 
 	writel(value, ioaddr + DMA_BUS_MODE);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c
index 61f54c99a7de..e5664da382f3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c
@@ -32,11 +32,12 @@
 #include "dwmac100.h"
 #include "dwmac_dma.h"
 
-static void dwmac100_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
-			      int aal, u32 dma_tx, u32 dma_rx, int atds)
+static void dwmac100_dma_init(void __iomem *ioaddr,
+			      struct stmmac_dma_cfg *dma_cfg,
+			      u32 dma_tx, u32 dma_rx, int atds)
 {
 	/* Enable Application Access by writing to DMA CSR0 */
-	writel(DMA_BUS_MODE_DEFAULT | (pbl << DMA_BUS_MODE_PBL_SHIFT),
+	writel(DMA_BUS_MODE_DEFAULT | (dma_cfg->pbl << DMA_BUS_MODE_PBL_SHIFT),
 	       ioaddr + DMA_BUS_MODE);
 
 	/* Mask interrupts by writing to CSR7 */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 577316de6ba8..0946546d6dcd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -97,27 +97,29 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr, int pbl,
 	writel(dma_rx_phy, ioaddr + DMA_CHAN_RX_BASE_ADDR(channel));
 }
 
-static void dwmac4_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
-			    int aal, u32 dma_tx, u32 dma_rx, int atds)
+static void dwmac4_dma_init(void __iomem *ioaddr,
+			    struct stmmac_dma_cfg *dma_cfg,
+			    u32 dma_tx, u32 dma_rx, int atds)
 {
 	u32 value = readl(ioaddr + DMA_SYS_BUS_MODE);
 	int i;
 
 	/* Set the Fixed burst mode */
-	if (fb)
+	if (dma_cfg->fixed_burst)
 		value |= DMA_SYS_BUS_FB;
 
 	/* Mixed Burst has no effect when fb is set */
-	if (mb)
+	if (dma_cfg->mixed_burst)
 		value |= DMA_SYS_BUS_MB;
 
-	if (aal)
+	if (dma_cfg->aal)
 		value |= DMA_SYS_BUS_AAL;
 
 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
 
 	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
-		dwmac4_dma_init_channel(ioaddr, pbl, dma_tx, dma_rx, i);
+		dwmac4_dma_init_channel(ioaddr, dma_cfg->pbl,
+					dma_tx, dma_rx, i);
 }
 
 static void _dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 channel)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 14366800e5e6..b1e42ddf0370 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1595,11 +1595,7 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 		return ret;
 	}
 
-	priv->hw->dma->init(priv->ioaddr,
-			    priv->plat->dma_cfg->pbl,
-			    priv->plat->dma_cfg->fixed_burst,
-			    priv->plat->dma_cfg->mixed_burst,
-			    priv->plat->dma_cfg->aal,
+	priv->hw->dma->init(priv->ioaddr, priv->plat->dma_cfg,
 			    priv->dma_tx_phy, priv->dma_rx_phy, atds);
 
 	if (priv->synopsys_id >= DWMAC_CORE_4_00) {
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v2 3/6] net: stmmac: stmmac_platform: fix parsing of DT binding
  2016-12-05  9:10 [PATCH v2 0/6] net: stmmac: make DMA programmable burst length more configurable Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 1/6] net: stmmac: return error if no DMA configuration is found Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 2/6] net: stmmac: simplify the common DMA init API Niklas Cassel
@ 2016-12-05  9:10 ` Niklas Cassel
  2016-12-05 16:12   ` Niklas Cassel
  2016-12-05  9:10 ` [PATCH v2 4/6] net: stmmac: dwmac1000: fix define DMA_BUS_MODE_RPBL_MASK Niklas Cassel
  3 siblings, 1 reply; 6+ messages in thread
From: Niklas Cassel @ 2016-12-05  9:10 UTC (permalink / raw)
  To: Giuseppe Cavallaro, Alexandre Torgue; +Cc: Niklas Cassel, netdev, linux-kernel

From: Niklas Cassel <niklas.cassel@axis.com>

commit 64c3b252e9fc ("net: stmmac: fixed the pbl setting with DT")
changed the parsing of the DT binding.

Before 64c3b252e9fc, snps,fixed-burst and snps,mixed-burst were parsed
regardless if the property snps,pbl existed or not.
After the commit, fixed burst and mixed burst are only parsed if
snps,pbl exists. Now when snps,aal has been added, it too is only
parsed if snps,pbl exists.

Since the DT binding does not specify that fixed burst, mixed burst
or aal depend on snps,pbl being specified, undo changes introduced
by 64c3b252e9fc.

The issue commit 64c3b252e9fc ("net: stmmac: fixed the pbl setting with
DT") tries to address is solved in another way:
The databook specifies that all values other than
1, 2, 4, 8, 16, or 32 results in undefined behavior,
so snps,pbl = <0> is invalid.

If pbl is 0 after parsing, set pbl to DEFAULT_DMA_PBL.
This handles the case where the property is omitted, and also handles
the case where the property is specified without any data.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  |  3 +++
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  | 27 +++++++++++-----------
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b1e42ddf0370..2298c4d109fb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1586,6 +1586,9 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 		return -EINVAL;
 	}
 
+	if (!priv->plat->dma_cfg->pbl)
+		priv->plat->dma_cfg->pbl = DEFAULT_DMA_PBL;
+
 	if (priv->extend_desc && (priv->mode == STMMAC_RING_MODE))
 		atds = 1;
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 98bf86d64d96..59e1740479fc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -301,21 +301,20 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 		plat->force_sf_dma_mode = 1;
 	}
 
-	if (of_find_property(np, "snps,pbl", NULL)) {
-		dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*dma_cfg),
-				       GFP_KERNEL);
-		if (!dma_cfg) {
-			stmmac_remove_config_dt(pdev, plat);
-			return ERR_PTR(-ENOMEM);
-		}
-		plat->dma_cfg = dma_cfg;
-		of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl);
-		dma_cfg->aal = of_property_read_bool(np, "snps,aal");
-		dma_cfg->fixed_burst =
-			of_property_read_bool(np, "snps,fixed-burst");
-		dma_cfg->mixed_burst =
-			of_property_read_bool(np, "snps,mixed-burst");
+	dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*dma_cfg),
+			       GFP_KERNEL);
+	if (!dma_cfg) {
+		stmmac_remove_config_dt(pdev, plat);
+		return ERR_PTR(-ENOMEM);
 	}
+	plat->dma_cfg = dma_cfg;
+
+	of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl);
+
+	dma_cfg->aal = of_property_read_bool(np, "snps,aal");
+	dma_cfg->fixed_burst = of_property_read_bool(np, "snps,fixed-burst");
+	dma_cfg->mixed_burst = of_property_read_bool(np, "snps,mixed-burst");
+
 	plat->force_thresh_dma_mode = of_property_read_bool(np, "snps,force_thresh_dma_mode");
 	if (plat->force_thresh_dma_mode) {
 		plat->force_sf_dma_mode = 0;
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v2 4/6] net: stmmac: dwmac1000: fix define DMA_BUS_MODE_RPBL_MASK
  2016-12-05  9:10 [PATCH v2 0/6] net: stmmac: make DMA programmable burst length more configurable Niklas Cassel
                   ` (2 preceding siblings ...)
  2016-12-05  9:10 ` [PATCH v2 3/6] net: stmmac: stmmac_platform: fix parsing of DT binding Niklas Cassel
@ 2016-12-05  9:10 ` Niklas Cassel
  3 siblings, 0 replies; 6+ messages in thread
From: Niklas Cassel @ 2016-12-05  9:10 UTC (permalink / raw)
  To: Giuseppe Cavallaro, Alexandre Torgue; +Cc: Niklas Cassel, netdev, linux-kernel

From: Niklas Cassel <niklas.cassel@axis.com>

DMA_BUS_MODE_RPBL_MASK is really 6 bits,
just like DMA_BUS_MODE_PBL_MASK.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac1000.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index ff3e5ab39bd0..52b9407a8a39 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
@@ -225,7 +225,7 @@ enum rx_tx_priority_ratio {
 
 #define DMA_BUS_MODE_FB		0x00010000	/* Fixed burst */
 #define DMA_BUS_MODE_MB		0x04000000	/* Mixed burst */
-#define DMA_BUS_MODE_RPBL_MASK	0x003e0000	/* Rx-Programmable Burst Len */
+#define DMA_BUS_MODE_RPBL_MASK	0x007e0000	/* Rx-Programmable Burst Len */
 #define DMA_BUS_MODE_RPBL_SHIFT	17
 #define DMA_BUS_MODE_USP	0x00800000
 #define DMA_BUS_MODE_MAXPBL	0x01000000
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v2 3/6] net: stmmac: stmmac_platform: fix parsing of DT binding
  2016-12-05  9:10 ` [PATCH v2 3/6] net: stmmac: stmmac_platform: fix parsing of DT binding Niklas Cassel
@ 2016-12-05 16:12   ` Niklas Cassel
  0 siblings, 0 replies; 6+ messages in thread
From: Niklas Cassel @ 2016-12-05 16:12 UTC (permalink / raw)
  To: Giuseppe Cavallaro, Alexandre Torgue; +Cc: netdev, linux-kernel

On 12/05/2016 10:10 AM, Niklas Cassel wrote:
> From: Niklas Cassel <niklas.cassel@axis.com>
>
> commit 64c3b252e9fc ("net: stmmac: fixed the pbl setting with DT")
> changed the parsing of the DT binding.
>
> Before 64c3b252e9fc, snps,fixed-burst and snps,mixed-burst were parsed
> regardless if the property snps,pbl existed or not.
> After the commit, fixed burst and mixed burst are only parsed if
> snps,pbl exists. Now when snps,aal has been added, it too is only
> parsed if snps,pbl exists.
>
> Since the DT binding does not specify that fixed burst, mixed burst
> or aal depend on snps,pbl being specified, undo changes introduced
> by 64c3b252e9fc.
>
> The issue commit 64c3b252e9fc ("net: stmmac: fixed the pbl setting with
> DT") tries to address is solved in another way:
> The databook specifies that all values other than
> 1, 2, 4, 8, 16, or 32 results in undefined behavior,
> so snps,pbl = <0> is invalid.
>
> If pbl is 0 after parsing, set pbl to DEFAULT_DMA_PBL.
> This handles the case where the property is omitted, and also handles
> the case where the property is specified without any data.
>
> Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  |  3 +++
>  .../net/ethernet/stmicro/stmmac/stmmac_platform.c  | 27 +++++++++++-----------
>  2 files changed, 16 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index b1e42ddf0370..2298c4d109fb 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1586,6 +1586,9 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
>  		return -EINVAL;
>  	}
>  
> +	if (!priv->plat->dma_cfg->pbl)
> +		priv->plat->dma_cfg->pbl = DEFAULT_DMA_PBL;
> +

Perhaps it is cleaner to have this "fallback to a default value" in
stmmac_probe_config_dt, right after
of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl),
since the only other place where the pbl is set, is from PCI glue.

The PCI glue should set a correct pbl value, and shouldn't need to
rely on a default value.
The code in stmmac_init_dma_engine could then, instead of
"fallback to a default value", return an error if pbl == 0.

>  	if (priv->extend_desc && (priv->mode == STMMAC_RING_MODE))
>  		atds = 1;
>  
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 98bf86d64d96..59e1740479fc 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -301,21 +301,20 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>  		plat->force_sf_dma_mode = 1;
>  	}
>  
> -	if (of_find_property(np, "snps,pbl", NULL)) {
> -		dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*dma_cfg),
> -				       GFP_KERNEL);
> -		if (!dma_cfg) {
> -			stmmac_remove_config_dt(pdev, plat);
> -			return ERR_PTR(-ENOMEM);
> -		}
> -		plat->dma_cfg = dma_cfg;
> -		of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl);
> -		dma_cfg->aal = of_property_read_bool(np, "snps,aal");
> -		dma_cfg->fixed_burst =
> -			of_property_read_bool(np, "snps,fixed-burst");
> -		dma_cfg->mixed_burst =
> -			of_property_read_bool(np, "snps,mixed-burst");
> +	dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*dma_cfg),
> +			       GFP_KERNEL);
> +	if (!dma_cfg) {
> +		stmmac_remove_config_dt(pdev, plat);
> +		return ERR_PTR(-ENOMEM);
>  	}
> +	plat->dma_cfg = dma_cfg;
> +
> +	of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl);
> +
> +	dma_cfg->aal = of_property_read_bool(np, "snps,aal");
> +	dma_cfg->fixed_burst = of_property_read_bool(np, "snps,fixed-burst");
> +	dma_cfg->mixed_burst = of_property_read_bool(np, "snps,mixed-burst");
> +
>  	plat->force_thresh_dma_mode = of_property_read_bool(np, "snps,force_thresh_dma_mode");
>  	if (plat->force_thresh_dma_mode) {
>  		plat->force_sf_dma_mode = 0;

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2016-12-05 16:12 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-12-05  9:10 [PATCH v2 0/6] net: stmmac: make DMA programmable burst length more configurable Niklas Cassel
2016-12-05  9:10 ` [PATCH v2 1/6] net: stmmac: return error if no DMA configuration is found Niklas Cassel
2016-12-05  9:10 ` [PATCH v2 2/6] net: stmmac: simplify the common DMA init API Niklas Cassel
2016-12-05  9:10 ` [PATCH v2 3/6] net: stmmac: stmmac_platform: fix parsing of DT binding Niklas Cassel
2016-12-05 16:12   ` Niklas Cassel
2016-12-05  9:10 ` [PATCH v2 4/6] net: stmmac: dwmac1000: fix define DMA_BUS_MODE_RPBL_MASK Niklas Cassel

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