From: Niklas Cassel <niklas.cassel@xxxxxxxx>
The driver currently always sets the PBLx8/PBLx4 bit, which means that
the pbl values configured via the pbl/txpbl/rxpbl DT properties are
always multiplied by 8/4 in the hardware.
In order to allow the DT to configure lower pbl values, while at the
same time not changing behavior of any existing device trees using the
pbl/txpbl/rxpbl settings, add a property to disable the multiplication
of the pbl by 8/4 in the hardware.
Suggested-by: Rabin Vincent <rabinv@xxxxxxxx>
Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx>
---
Documentation/devicetree/bindings/net/stmmac.txt | 2 ++
Documentation/networking/stmmac.txt | 5 ++++-
drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c | 3 ++-
drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c | 3 ++-
drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c | 2 ++
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 1 +
include/linux/stmmac.h | 1 +
7 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index 8080038ff1b2..128da752fec9 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -39,6 +39,8 @@ Optional properties:
If set, DMA tx will use this value rather than snps,pbl.
- snps,rxpbl Rx Programmable Burst Length. Only for GMAC and newer.
If set, DMA rx will use this value rather than snps,pbl.
+- snps,no-pbl-x8 Don't multiply the pbl/txpbl/rxpbl values by 8.
+ For core rev < 3.50, don't multiply the values by 4.
- snps,aal Address-Aligned Beats
- snps,fixed-burst Program the DMA to use the fixed burst mode
- snps,mixed-burst Program the DMA to use the mixed burst mode
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
index 82c8e496b4bb..d3376c5fbcf0 100644
--- a/Documentation/networking/stmmac.txt
+++ b/Documentation/networking/stmmac.txt
@@ -153,8 +153,9 @@ Where:
o dma_cfg: internal DMA parameters
o pbl: the Programmable Burst Length is maximum number of beats to
be transferred in one DMA transaction.
- GMAC also enables the 4xPBL by default.
+ GMAC also enables the 4xPBL by default. (8xPBL for GMAC 3.50 and newer)
o txpbl/rxpbl: GMAC and newer supports independent DMA pbl for tx/rx.
+ o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
o fixed_burst/mixed_burst/aal
o clk_csr: fixed CSR Clock range selection.
o has_gmac: uses the GMAC core.
@@ -209,6 +210,7 @@ struct stmmac_dma_cfg {
int pbl;
int txpbl;
int rxpbl;
+ bool pblx8;
int fixed_burst;
int mixed_burst;
bool aal;
@@ -220,6 +222,7 @@ Where:
If set, DMA tx will use this value rather than pbl.
o rxpbl: Receive Programmable Burst Length. Only for GMAC and newer.
If set, DMA rx will use this value rather than pbl.
+ o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
o fixed_burst: program the DMA to use the fixed burst mode
o mixed_burst: program the DMA to use the mixed burst mode
o aal: Address-Aligned Beats
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index 1dd34fb4c1a9..1d313af647b4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -96,7 +96,8 @@ static void dwmac1000_dma_init(void __iomem *ioaddr,
* Note: before stmmac core 3.50 this mode bit was 4xPBL, and
* post 3.5 mode bit acts as 8*PBL.
*/
- value |= DMA_BUS_MODE_MAXPBL;
+ if (dma_cfg->pblx8)
+ value |= DMA_BUS_MODE_MAXPBL;
value |= DMA_BUS_MODE_USP;
value &= ~(DMA_BUS_MODE_PBL_MASK | DMA_BUS_MODE_RPBL_MASK);
value |= (txpbl << DMA_BUS_MODE_PBL_SHIFT);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 0bf47825bfeb..0f7110d19a4a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -82,7 +82,8 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr,
* on each channel
*/
value = readl(ioaddr + DMA_CHAN_CONTROL(channel));
- value = value | DMA_BUS_MODE_PBL;
+ if (dma_cfg->pblx8)
+ value = value | DMA_BUS_MODE_PBL;
writel(value, ioaddr + DMA_CHAN_CONTROL(channel));
value = readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 56c8a2342c14..a2831773431a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
@@ -81,6 +81,7 @@ static void stmmac_default_data(struct plat_stmmacenet_data *plat)
plat->mdio_bus_data->phy_mask = 0;
plat->dma_cfg->pbl = 32;
+ plat->dma_cfg->pblx8 = true;
/* TODO: AXI */
/* Set default value for multicast hash bins */
@@ -115,6 +116,7 @@ static int quark_default_data(struct plat_stmmacenet_data *plat,
plat->mdio_bus_data->phy_mask = 0;
plat->dma_cfg->pbl = 16;
+ plat->dma_cfg->pblx8 = true;
plat->dma_cfg->fixed_burst = 1;
/* AXI (TODO) */
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 29faff42a5ea..3a713862f0a3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -314,6 +314,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl);
of_property_read_u32(np, "snps,txpbl", &dma_cfg->txpbl);
of_property_read_u32(np, "snps,rxpbl", &dma_cfg->rxpbl);
+ dma_cfg->pblx8 = !of_property_read_bool(np, "snps,no-pbl-x8");
dma_cfg->aal = of_property_read_bool(np, "snps,aal");
dma_cfg->fixed_burst = of_property_read_bool(np, "snps,fixed-burst");
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index c8a7c6b278da..05a8243017b0 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -90,6 +90,7 @@ struct stmmac_dma_cfg {
int pbl;
int txpbl;
int rxpbl;
+ bool pblx8;
int fixed_burst;
int mixed_burst;
bool aal;
--
2.1.4
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