forcedeth: allow to silence "TX timeout" debug messages

This adds a new module parameter "debug_tx_timeout" to silence most
debug messages in case of TX timeout. These messages don't provide a
signal/noise ratio high enough for production systems and, with ~30kB
logged each time, they tend to add to a cascade effect if the system
is already under stress (memory pressure, disk, etc.).

By default, the parameter is clear, meaning that only a single warning
will be reported.

Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index eca089d42593510ce81d9e9063157cd93a0840ee..0edc5a6340211c3d2e085053761404373d23a706 100644 (file)
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c
@@ -891,6 +891,11 @@ enum {
 };
 static int dma_64bit = NV_DMA_64BIT_ENABLED;
 
+/*
+ * Debug output control for tx_timeout
+ */
+static bool debug_tx_timeout = false;
+
 /*
  * Crossover Detection
  * Realtek 8201 phy + some OEM boards do not work properly.
@@ -2477,56 +2482,64 @@ static void nv_tx_timeout(struct net_device *dev)
        u32 status;
        union ring_type put_tx;
        int saved_tx_limit;
-       int i;
 
        if (np->msi_flags & NV_MSI_X_ENABLED)
                status = readl(base + NvRegMSIXIrqStatus) & NVREG_IRQSTAT_MASK;
        else
                status = readl(base + NvRegIrqStatus) & NVREG_IRQSTAT_MASK;
 
-       netdev_info(dev, "Got tx_timeout. irq: %08x\n", status);
+       netdev_warn(dev, "Got tx_timeout. irq status: %08x\n", status);
 
-       netdev_info(dev, "Ring at %lx\n", (unsigned long)np->ring_addr);
-       netdev_info(dev, "Dumping tx registers\n");
-       for (i = 0; i <= np->register_size; i += 32) {
-               netdev_info(dev,
-                           "%3x: %08x %08x %08x %08x %08x %08x %08x %08x\n",
-                           i,
-                           readl(base + i + 0), readl(base + i + 4),
-                           readl(base + i + 8), readl(base + i + 12),
-                           readl(base + i + 16), readl(base + i + 20),
-                           readl(base + i + 24), readl(base + i + 28));
-       }
-       netdev_info(dev, "Dumping tx ring\n");
-       for (i = 0; i < np->tx_ring_size; i += 4) {
-               if (!nv_optimized(np)) {
-                       netdev_info(dev,
-                                   "%03x: %08x %08x // %08x %08x // %08x %08x // %08x %08x\n",
-                                   i,
-                                   le32_to_cpu(np->tx_ring.orig[i].buf),
-                                   le32_to_cpu(np->tx_ring.orig[i].flaglen),
-                                   le32_to_cpu(np->tx_ring.orig[i+1].buf),
-                                   le32_to_cpu(np->tx_ring.orig[i+1].flaglen),
-                                   le32_to_cpu(np->tx_ring.orig[i+2].buf),
-                                   le32_to_cpu(np->tx_ring.orig[i+2].flaglen),
-                                   le32_to_cpu(np->tx_ring.orig[i+3].buf),
-                                   le32_to_cpu(np->tx_ring.orig[i+3].flaglen));
-               } else {
+       if (unlikely(debug_tx_timeout)) {
+               int i;
+
+               netdev_info(dev, "Ring at %lx\n", (unsigned long)np->ring_addr);
+               netdev_info(dev, "Dumping tx registers\n");
+               for (i = 0; i <= np->register_size; i += 32) {
                        netdev_info(dev,
-                                   "%03x: %08x %08x %08x // %08x %08x %08x // %08x %08x %08x // %08x %08x %08x\n",
+                                   "%3x: %08x %08x %08x %08x "
+                                   "%08x %08x %08x %08x\n",
                                    i,
-                                   le32_to_cpu(np->tx_ring.ex[i].bufhigh),
-                                   le32_to_cpu(np->tx_ring.ex[i].buflow),
-                                   le32_to_cpu(np->tx_ring.ex[i].flaglen),
-                                   le32_to_cpu(np->tx_ring.ex[i+1].bufhigh),
-                                   le32_to_cpu(np->tx_ring.ex[i+1].buflow),
-                                   le32_to_cpu(np->tx_ring.ex[i+1].flaglen),
-                                   le32_to_cpu(np->tx_ring.ex[i+2].bufhigh),
-                                   le32_to_cpu(np->tx_ring.ex[i+2].buflow),
-                                   le32_to_cpu(np->tx_ring.ex[i+2].flaglen),
-                                   le32_to_cpu(np->tx_ring.ex[i+3].bufhigh),
-                                   le32_to_cpu(np->tx_ring.ex[i+3].buflow),
-                                   le32_to_cpu(np->tx_ring.ex[i+3].flaglen));
+                                   readl(base + i + 0), readl(base + i + 4),
+                                   readl(base + i + 8), readl(base + i + 12),
+                                   readl(base + i + 16), readl(base + i + 20),
+                                   readl(base + i + 24), readl(base + i + 28));
+               }
+               netdev_info(dev, "Dumping tx ring\n");
+               for (i = 0; i < np->tx_ring_size; i += 4) {
+                       if (!nv_optimized(np)) {
+                               netdev_info(dev,
+                                           "%03x: %08x %08x // %08x %08x "
+                                           "// %08x %08x // %08x %08x\n",
+                                           i,
+                                           le32_to_cpu(np->tx_ring.orig[i].buf),
+                                           le32_to_cpu(np->tx_ring.orig[i].flaglen),
+                                           le32_to_cpu(np->tx_ring.orig[i+1].buf),
+                                           le32_to_cpu(np->tx_ring.orig[i+1].flaglen),
+                                           le32_to_cpu(np->tx_ring.orig[i+2].buf),
+                                           le32_to_cpu(np->tx_ring.orig[i+2].flaglen),
+                                           le32_to_cpu(np->tx_ring.orig[i+3].buf),
+                                           le32_to_cpu(np->tx_ring.orig[i+3].flaglen));
+                       } else {
+                               netdev_info(dev,
+                                           "%03x: %08x %08x %08x "
+                                           "// %08x %08x %08x "
+                                           "// %08x %08x %08x "
+                                           "// %08x %08x %08x\n",
+                                           i,
+                                           le32_to_cpu(np->tx_ring.ex[i].bufhigh),
+                                           le32_to_cpu(np->tx_ring.ex[i].buflow),
+                                           le32_to_cpu(np->tx_ring.ex[i].flaglen),
+                                           le32_to_cpu(np->tx_ring.ex[i+1].bufhigh),
+                                           le32_to_cpu(np->tx_ring.ex[i+1].buflow),
+                                           le32_to_cpu(np->tx_ring.ex[i+1].flaglen),
+                                           le32_to_cpu(np->tx_ring.ex[i+2].bufhigh),
+                                           le32_to_cpu(np->tx_ring.ex[i+2].buflow),
+                                           le32_to_cpu(np->tx_ring.ex[i+2].flaglen),
+                                           le32_to_cpu(np->tx_ring.ex[i+3].bufhigh),
+                                           le32_to_cpu(np->tx_ring.ex[i+3].buflow),
+                                           le32_to_cpu(np->tx_ring.ex[i+3].flaglen));
+                       }
                }
        }
 
@@ -6157,6 +6170,9 @@ module_param(phy_cross, int, 0);
 MODULE_PARM_DESC(phy_cross, "Phy crossover detection for Realtek 8201 phy is enabled by setting to 1 and disabled by setting to 0.");
 module_param(phy_power_down, int, 0);
 MODULE_PARM_DESC(phy_power_down, "Power down phy and disable link when interface is down (1), or leave phy powered up (0).");
+module_param(debug_tx_timeout, bool, 0);
+MODULE_PARM_DESC(debug_tx_timeout,
+                "Dump tx related registers and ring when tx_timeout happens");
 
 MODULE_AUTHOR("Manfred Spraul <manfred@colorfullife.com>");
 MODULE_DESCRIPTION("Reverse Engineered nForce ethernet driver");