net: stmmac: dwmac4: Re-enable MAC Rx before powering down

ed-blake1 · davem330 · commit 1579f678fb43 · 2017-09-28T10:19:02.000-07:00
Re-enable the MAC receiver by setting CONFIG_RE before powering down,
as instructed in section 6.3.5.1 of [1].  Without this the MAC fails
to receive WoL packets and never wakes up.

[1] DWC Ethernet QoS Databook 4.10a October 2014

Signed-off-by: Ed Blake &lt;ed.blake@sondrel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -296,6 +296,7 @@ static void dwmac4_pmt(struct mac_device_info *hw, unsigned long mode)
 {
 	void __iomem *ioaddr = hw->pcsr;
 	unsigned int pmt = 0;
+	u32 config;
 
 	if (mode & WAKE_MAGIC) {
 		pr_debug("GMAC: WOL Magic frame\n");
@@ -306,6 +307,12 @@ static void dwmac4_pmt(struct mac_device_info *hw, unsigned long mode)
 		pmt |= power_down | global_unicast | wake_up_frame_en;
 	}
 
+	if (pmt) {
+		/* The receiver must be enabled for WOL before powering down */
+		config = readl(ioaddr + GMAC_CONFIG);
+		config |= GMAC_CONFIG_RE;
+		writel(config, ioaddr + GMAC_CONFIG);
+	}
 	writel(pmt, ioaddr + GMAC_PMT);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -296,6 +296,7 @@ static void dwmac4_pmt(struct mac_device_info *hw, unsigned long mode)`
`296`	`296`	`{`
`297`	`297`	`void __iomem *ioaddr = hw->pcsr;`
`298`	`298`	`unsigned int pmt = 0;`
	`299`	`+ u32 config;`
`299`	`300`
`300`	`301`	`if (mode & WAKE_MAGIC) {`
`301`	`302`	`pr_debug("GMAC: WOL Magic frame\n");`
`@@ -306,6 +307,12 @@ static void dwmac4_pmt(struct mac_device_info *hw, unsigned long mode)`
`306`	`307`	`pmt \|= power_down \| global_unicast \| wake_up_frame_en;`
`307`	`308`	`}`
`308`	`309`
	`310`	`+ if (pmt) {`
	`311`	`+ /* The receiver must be enabled for WOL before powering down */`
	`312`	`+ config = readl(ioaddr + GMAC_CONFIG);`
	`313`	`+ config \|= GMAC_CONFIG_RE;`
	`314`	`+ writel(config, ioaddr + GMAC_CONFIG);`
	`315`	`+ }`
`309`	`316`	`writel(pmt, ioaddr + GMAC_PMT);`
`310`	`317`	`}`
`311`	`318`