net: bcmgenet: test RBUF_ACPI_EN when resuming

When the GENET driver resumes from deep sleep the UMAC_CMD
register may not be accessible and therefore should not be
accessed from bcmgenet_wol_power_up_cfg() if the GENET has
been reset.

This commit adds a check of the RBUF_ACPI_EN flag when Wake
on Filter is enabled. A clear flag indicates that the GENET
hardware must have been reset so the remainder of the
hardware programming is bypassed.

Fixes: f50932cca632 ("net: bcmgenet: add WAKE_FILTER support")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
index def990d..1c86edd 100644 (file)
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
@@ -229,9 +229,13 @@ void bcmgenet_wol_power_up_cfg(struct bcmgenet_priv *priv,
        }
 
        /* Disable WAKE_FILTER Detection */
-       reg = bcmgenet_hfb_reg_readl(priv, HFB_CTRL);
-       reg &= ~(RBUF_HFB_EN | RBUF_ACPI_EN);
-       bcmgenet_hfb_reg_writel(priv, reg, HFB_CTRL);
+       if (priv->wolopts & WAKE_FILTER) {
+               reg = bcmgenet_hfb_reg_readl(priv, HFB_CTRL);
+               if (!(reg & RBUF_ACPI_EN))
+                       return; /* already reset so skip the rest */
+               reg &= ~(RBUF_HFB_EN | RBUF_ACPI_EN);
+               bcmgenet_hfb_reg_writel(priv, reg, HFB_CTRL);
+       }
 
        /* Disable CRC Forward */
        reg = bcmgenet_umac_readl(priv, UMAC_CMD);