[PATCH] NET: dwmac: Make dwmac reset unconditional

[Eugeniy Paltsev]

Unconditional reset dwmac before HW init if reset controller is present.

In existing implementation we reset dwmac only after second module
probing:
(module load -> unload -> load again [reset happens])

Now we reset dwmac at every module load:
(module load [reset happens] -> unload -> load again [reset happens])

Also some reset controllers have only reset callback instead of
assert + deassert callbacks pair, so handle this case.

Signed-off-by: Eugeniy Paltsev <eugeniy.palt...@synopsys.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c 
b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 12236da..c7b3d0d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4096,8 +4096,15 @@ int stmmac_dvr_probe(struct device *device,
        if ((phyaddr >= 0) && (phyaddr <= 31))
                priv->plat->phy_addr = phyaddr;
 
-       if (priv->plat->stmmac_rst)
+       if (priv->plat->stmmac_rst) {
+               ret = reset_control_assert(priv->plat->stmmac_rst);
                reset_control_deassert(priv->plat->stmmac_rst);
+               /* Some reset controllers have only reset callback instead of
+                * assert + deassert callbacks pair.
+                */
+               if (ret == -ENOTSUPP)
+                       reset_control_reset(priv->plat->stmmac_rst);
+       }
 
        /* Init MAC and get the capabilities */
        ret = stmmac_hw_init(priv);
-- 
2.9.3