stmmac: do not fail when the timer cannot be used.

If the external timer cannot be used the driver
will continue to work without mitigation.

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

2 files changed, 29 insertions, 22 deletions

diff --git a/drivers/net/stmmac/stmmac_main.c b/drivers/net/stmmac/stmmac_main.c
index c2f14dc9ba2..9542995ba66 100644
--- a/drivers/net/stmmac/stmmac_main.c
+++ b/drivers/net/stmmac/stmmac_main.c
@@ -416,13 +416,8 @@ static void init_dma_desc_rings(struct net_device *dev)
         unsigned int txsize = priv->dma_tx_size;
         unsigned int rxsize = priv->dma_rx_size;
         unsigned int bfsize = priv->dma_buf_sz;
-        int buff2_needed = 0;
-        int dis_ic = 0;
+        int buff2_needed = 0, dis_ic = 0;
 
-#ifdef CONFIG_STMMAC_TIMER
-        /* Using Timers disable interrupts on completion for the reception */
-        dis_ic = 1;
-#endif
         /* Set the Buffer size according to the MTU;
          * indeed, in case of jumbo we need to bump-up the buffer sizes.
          */
@@ -437,6 +432,11 @@ static void init_dma_desc_rings(struct net_device *dev)
         else
                 bfsize = DMA_BUFFER_SIZE;
 
+#ifdef CONFIG_STMMAC_TIMER
+        /* Disable interrupts on completion for the reception if timer is on */
+        if (likely(priv->tm->enable))
+                dis_ic = 1;
+#endif
         /* If the MTU exceeds 8k so use the second buffer in the chain */
         if (bfsize >= BUF_SIZE_8KiB)
                 buff2_needed = 1;
@@ -809,20 +809,22 @@ static void stmmac_tx(struct stmmac_priv *priv)
 
 static inline void stmmac_enable_irq(struct stmmac_priv *priv)
 {
-#ifndef CONFIG_STMMAC_TIMER
-        writel(DMA_INTR_DEFAULT_MASK, priv->dev->base_addr + DMA_INTR_ENA);
-#else
-        priv->tm->timer_start(tmrate);
+#ifdef CONFIG_STMMAC_TIMER
+        if (likely(priv->tm->enable))
+                priv->tm->timer_start(tmrate);
+        else
 #endif
+        writel(DMA_INTR_DEFAULT_MASK, priv->dev->base_addr + DMA_INTR_ENA);
 }
 
 static inline void stmmac_disable_irq(struct stmmac_priv *priv)
 {
-#ifndef CONFIG_STMMAC_TIMER
-        writel(0, priv->dev->base_addr + DMA_INTR_ENA);
-#else
-        priv->tm->timer_stop();
+#ifdef CONFIG_STMMAC_TIMER
+        if (likely(priv->tm->enable))
+                priv->tm->timer_stop();
+        else
 #endif
+        writel(0, priv->dev->base_addr + DMA_INTR_ENA);
 }
 
 static int stmmac_has_work(struct stmmac_priv *priv)
@@ -1031,22 +1033,23 @@ static int stmmac_open(struct net_device *dev)
         }
 
 #ifdef CONFIG_STMMAC_TIMER
-        priv->tm = kmalloc(sizeof(struct stmmac_timer *), GFP_KERNEL);
+        priv->tm = kzalloc(sizeof(struct stmmac_timer *), GFP_KERNEL);
         if (unlikely(priv->tm == NULL)) {
                 pr_err("%s: ERROR: timer memory alloc failed \n", __func__);
                 return -ENOMEM;
         }
         priv->tm->freq = tmrate;
 
-        /* Test if the HW timer can be actually used.
-         * In case of failure continue with no timer. */
+        /* Test if the external timer can be actually used.
+         * In case of failure continue without timer. */
         if (unlikely((stmmac_open_ext_timer(dev, priv->tm)) < 0)) {
-                pr_warning("stmmaceth: cannot attach the HW timer\n");
+                pr_warning("stmmaceth: cannot attach the external timer.\n");
                 tmrate = 0;
                 priv->tm->freq = 0;
                 priv->tm->timer_start = stmmac_no_timer_started;
                 priv->tm->timer_stop = stmmac_no_timer_stopped;
-        }
+        } else
+                priv->tm->enable = 1;
 #endif
 
         /* Create and initialize the TX/RX descriptors chains. */
@@ -1322,9 +1325,11 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
         /* Interrupt on completition only for the latest segment */
         priv->mac_type->ops->close_tx_desc(desc);
+
 #ifdef CONFIG_STMMAC_TIMER
-        /* Clean IC while using timers */
-        priv->mac_type->ops->clear_tx_ic(desc);
+        /* Clean IC while using timer */
+        if (likely(priv->tm->enable))
+                priv->mac_type->ops->clear_tx_ic(desc);
 #endif
         /* To avoid raise condition */
         priv->mac_type->ops->set_tx_owner(first);
@@ -2028,7 +2033,8 @@ static int stmmac_suspend(struct platform_device *pdev, pm_message_t state)
 
 #ifdef CONFIG_STMMAC_TIMER
                 priv->tm->timer_stop();
-                dis_ic = 1;
+                if (likely(priv->tm->enable))
+                        dis_ic = 1;
 #endif
                 napi_disable(&priv->napi);
 
diff --git a/drivers/net/stmmac/stmmac_timer.h b/drivers/net/stmmac/stmmac_timer.h
index f795cae3372..6863590d184 100644
--- a/drivers/net/stmmac/stmmac_timer.h
+++ b/drivers/net/stmmac/stmmac_timer.h
@@ -26,6 +26,7 @@ struct stmmac_timer {
         void (*timer_start) (unsigned int new_freq);
         void (*timer_stop) (void);
         unsigned int freq;
+        unsigned int enable;
 };
 
 /* Open the HW timer device and return 0 in case of success */