sfc: Do not reinitialise XAUI serdes before it has completed reset

falcon_reset_xaui() waits for XGXS reset to complete, but the XAUI
serdes reset may take longer.  It needs to check both reset active
bits.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/sfc/falcon_hwdefs.h

@@ -700,6 +700,8 @@
 /* XGXS/XAUI powerdown/reset register */
 #define XX_PWR_RST_REG 0x1300
 
+#define XX_SD_RST_ACT_LBN 16
+#define XX_SD_RST_ACT_WIDTH 1
 #define XX_PWRDND_EN_LBN 15
 #define XX_PWRDND_EN_WIDTH 1
 #define XX_PWRDNC_EN_LBN 14

drivers/net/sfc/falcon_xmac.c

@@ -64,13 +64,15 @@ int falcon_reset_xaui(struct efx_nic *efx)
 	efx_oword_t reg;
 	int count;
 
+	/* Start reset sequence */
 	EFX_POPULATE_DWORD_1(reg, XX_RST_XX_EN, 1);
 	falcon_write(efx, &reg, XX_PWR_RST_REG);
 
-	/* Give some time for the link to establish */
-	for (count = 0; count < 1000; count++) { /* wait upto 10ms */
+	/* Wait up to 10 ms for completion, then reinitialise */
+	for (count = 0; count < 1000; count++) {
 		falcon_read(efx, &reg, XX_PWR_RST_REG);
-		if (EFX_OWORD_FIELD(reg, XX_RST_XX_EN) == 0) {
+		if (EFX_OWORD_FIELD(reg, XX_RST_XX_EN) == 0 &&
+		    EFX_OWORD_FIELD(reg, XX_SD_RST_ACT) == 0) {
 			falcon_setup_xaui(efx);
 			return 0;
 		}