r8169: prevent excessive busy-waiting (2371408c) · Commits · 戴 / test

The MII registers read/write function blindly busy waits for an amount of 1000 us (1 ms), then up to 200 ms. These functions are called from irq disabled context. Depending on the clock management, it triggers lost ticks events. Since the value is way above the standard delay required for mii register access, it strangely looks like a bandaid against posted writes. Fixes http://bugzilla.kernel.org/show_bug.cgi?id=5947 Signed-off-by:

Francois Romieu <romieu@fr.zoreil.com>

drivers/net/r8169.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -484,13 +484,12 @@ static void mdio_write(void __iomem *ioaddr, int RegAddr, int value)
		int i;

		RTL_W32(PHYAR, 0x80000000 \| (RegAddr & 0xFF) << 16 \| value);
		udelay(1000);

		for (i = 2000; i > 0; i--) {
		for (i = 20; i > 0; i--) {
		/* Check if the RTL8169 has completed writing to the specified MII register */
		if (!(RTL_R32(PHYAR) & 0x80000000))
		break;
		udelay(100);
		udelay(25);
		}
		}

		@@ -499,15 +498,14 @@ static int mdio_read(void __iomem *ioaddr, int RegAddr)
		int i, value = -1;

		RTL_W32(PHYAR, 0x0 \| (RegAddr & 0xFF) << 16);
		udelay(1000);

		for (i = 2000; i > 0; i--) {
		for (i = 20; i > 0; i--) {
		/* Check if the RTL8169 has completed retrieving data from the specified MII register */
		if (RTL_R32(PHYAR) & 0x80000000) {
		value = (int) (RTL_R32(PHYAR) & 0xFFFF);
		break;
		}
		udelay(100);
		udelay(25);
		}
		return value;
		}

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