stmmac: do not fail when probe and there is no csr clk defined

On some platforms, for example where we are doing the bring-up,
the csr clock is not passed from the framework and the Ethernet
device driver is failing when it can work w/o any issues and
using the default values. So this patch just warnings the case
of the csr clock cannot be acquired but w/o failing the probe
step. I have just tested it on ST STiH415 SoC (ARM).

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 7 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 9f2435c53f57..db2de9a49952 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -107,7 +107,7 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
 #ifdef CONFIG_HAVE_CLK
 static inline int stmmac_clk_enable(struct stmmac_priv *priv)
 {
-        if (priv->stmmac_clk)
+        if (!IS_ERR(priv->stmmac_clk))
                 return clk_enable(priv->stmmac_clk);
 
         return 0;
@@ -115,17 +115,18 @@ static inline int stmmac_clk_enable(struct stmmac_priv *priv)
 
 static inline void stmmac_clk_disable(struct stmmac_priv *priv)
 {
-        if (priv->stmmac_clk)
-                clk_disable(priv->stmmac_clk);
+        if (IS_ERR(priv->stmmac_clk))
+                return;
+
+        clk_disable(priv->stmmac_clk);
 }
 static inline int stmmac_clk_get(struct stmmac_priv *priv)
 {
         priv->stmmac_clk = clk_get(priv->device, NULL);
 
-        if (IS_ERR(priv->stmmac_clk)) {
-                pr_err("%s: ERROR clk_get failed\n", __func__);
+        if (IS_ERR(priv->stmmac_clk))
                 return PTR_ERR(priv->stmmac_clk);
-        }
+
         return 0;
 }
 #else
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index efc42e1f9b4a..1a4cf8128f91 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -168,6 +168,9 @@ static void stmmac_clk_csr_set(struct stmmac_priv *priv)
 #ifdef CONFIG_HAVE_CLK
         u32 clk_rate;
 
+        if (IS_ERR(priv->stmmac_clk))
+                return;
+
         clk_rate = clk_get_rate(priv->stmmac_clk);
 
         /* Platform provided default clk_csr would be assumed valid
@@ -1923,7 +1926,7 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
         }
 
         if (stmmac_clk_get(priv))
-                goto error;
+                pr_warning("%s: warning: cannot get CSR clock\n", __func__);
 
         /* If a specific clk_csr value is passed from the platform
          * this means that the CSR Clock Range selection cannot be