Re: [PATCH] net: stmmac: add dcrs parameter
From: Giuseppe CAVALLARO
Date: Mon Aug 25 2014 - 08:51:37 EST
On 8/25/2014 2:34 PM, Chen-Yu Tsai wrote:
Hi,
On Mon, Aug 25, 2014 at 7:50 PM, Ley Foon Tan <lftan@xxxxxxxxxx> wrote:
This patch add the option to enable DCRS bit in GMAC control register.
Default is disabled if snps,dcrs is not defined.
For MII, Carrier Sense (CRS) must be asserted during transmission
whereas in RGMII, CRS is not. RGMII does not provide a way to signal
loss of carrier during a transmission.
When DCRS bit set high in control register, the MAC transmitter
ignore the (G)MII Carrier Sense signal during frame transmission
in the half-duplex mode. This request results in no errors generated
because of Loss of Carrier or No Carrier during such transmission.
Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx>
---
Documentation/devicetree/bindings/net/stmmac.txt | 4 ++++
drivers/net/ethernet/stmicro/stmmac/common.h | 3 ++-
drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c | 4 +++-
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 3 ++-
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 2 ++
include/linux/stmmac.h | 1 +
6 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index 9b03c57..a68e720 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -39,6 +39,10 @@ Optional properties:
further clocks may be specified in derived bindings.
- clock-names: One name for each entry in the clocks property, the
first one should be "stmmaceth".
+- snps,dcrs: Enable DCRS bit in GMAC control register. This DCRS bit makes the
+ MAC transmitter ignore the (G)MII CRS signal during frame transmission
+ in the half-duplex mode. This request results in no errors generated
Since you know this is only required under (G)MII, could you not re-use
the "phy-mode" property, instead of adding another one?
Better yet, use the "interface" field in the platform data. This way you'll
fix non-DT devices as well. You could then avoid touching the platform driver,
and just modify the driver core.
yes this is what I asked. Thx ChenYu for the this detail.
Ley Foon Tan, could you do that? Let me know
peppe
Cheers
ChenYu
+ because of Loss of Carrier or No Carrier during such transmission.
Examples:
diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index de507c3..9abe221 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -445,10 +445,11 @@ struct mac_device_info {
int multicast_filter_bins;
int unicast_filter_entries;
int mcast_bits_log2;
+ int dcrs;
};
struct mac_device_info *dwmac1000_setup(void __iomem *ioaddr, int mcbins,
- int perfect_uc_entries);
+ int perfect_uc_entries, int dcrs);
struct mac_device_info *dwmac100_setup(void __iomem *ioaddr);
void stmmac_set_mac_addr(void __iomem *ioaddr, u8 addr[6],
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index d8ef187..924d450 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -37,6 +37,7 @@ static void dwmac1000_core_init(struct mac_device_info *hw, int mtu)
void __iomem *ioaddr = hw->pcsr;
u32 value = readl(ioaddr + GMAC_CONTROL);
value |= GMAC_CORE_INIT;
+ value |= hw->dcrs;
if (mtu > 1500)
value |= GMAC_CONTROL_2K;
if (mtu > 2000)
@@ -409,7 +410,7 @@ static const struct stmmac_ops dwmac1000_ops = {
};
struct mac_device_info *dwmac1000_setup(void __iomem *ioaddr, int mcbins,
- int perfect_uc_entries)
+ int perfect_uc_entries, int dcrs)
{
struct mac_device_info *mac;
u32 hwid = readl(ioaddr + GMAC_VERSION);
@@ -422,6 +423,7 @@ struct mac_device_info *dwmac1000_setup(void __iomem *ioaddr, int mcbins,
mac->multicast_filter_bins = mcbins;
mac->unicast_filter_entries = perfect_uc_entries;
mac->mcast_bits_log2 = 0;
+ mac->dcrs = dcrs;
if (mac->multicast_filter_bins)
mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 08addd6..bf35b19 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2600,7 +2600,8 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
priv->dev->priv_flags |= IFF_UNICAST_FLT;
mac = dwmac1000_setup(priv->ioaddr,
priv->plat->multicast_filter_bins,
- priv->plat->unicast_filter_entries);
+ priv->plat->unicast_filter_entries,
+ priv->plat->dcrs);
} else {
mac = dwmac100_setup(priv->ioaddr);
}
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index bb524a9..07f895f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -227,6 +227,8 @@ static int stmmac_probe_config_dt(struct platform_device *pdev,
pr_warn("force_sf_dma_mode is ignored if force_thresh_dma_mode is set.");
}
+ plat->dcrs = of_property_read_bool(np, "snps,dcrs");
+
return 0;
}
#else
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index cd63851..6367f42 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -114,6 +114,7 @@ struct plat_stmmacenet_data {
int maxmtu;
int multicast_filter_bins;
int unicast_filter_entries;
+ int dcrs;
void (*fix_mac_speed)(void *priv, unsigned int speed);
void (*bus_setup)(void __iomem *ioaddr);
void *(*setup)(struct platform_device *pdev);
--
1.8.2.1
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