[openib-general] [PATCH][RFC] Turn on mthca debug unless EMBEDDED is selected

[Roland Dreier]

And here's a patch to make mthca debugging configurable at runtime via
a module option, and get rid of the Kconfig choice unless EMBEDDED is set.

Thoughts on this one?

--- infiniband/hw/mthca/Kconfig	(revision 6101)
+++ infiniband/hw/mthca/Kconfig	(working copy)
@@ -7,10 +7,11 @@ config INFINIBAND_MTHCA
 	  ("Tavor") and the MT25208 PCI Express HCA ("Arbel").
 
 config INFINIBAND_MTHCA_DEBUG
-	bool "Verbose debugging output"
+	bool "Verbose debugging output" if EMBEDDED
 	depends on INFINIBAND_MTHCA
-	default n
+	default y
 	---help---
-	  This option causes the mthca driver produce a bunch of debug
-	  messages.  Select this is you are developing the driver or
-	  trying to diagnose a problem.
+	  This option causes debugging code to be compiled into the
+	  mthca driver.  The output can be turned on via the
+	  debug_level module parameter (which can also be set after
+	  the driver is loaded through sysfs).
--- infiniband/hw/mthca/Makefile	(revision 6101)
+++ infiniband/hw/mthca/Makefile	(working copy)
@@ -1,9 +1,5 @@
 EXTRA_CFLAGS += -Idrivers/infiniband/include
 
-ifdef CONFIG_INFINIBAND_MTHCA_DEBUG
-EXTRA_CFLAGS += -DDEBUG
-endif
-
 obj-$(CONFIG_INFINIBAND_MTHCA) += ib_mthca.o
 
 ib_mthca-y :=	mthca_main.o mthca_cmd.o mthca_profile.o mthca_reset.o \
--- infiniband/hw/mthca/mthca_dev.h	(revision 6101)
+++ infiniband/hw/mthca/mthca_dev.h	(working copy)
@@ -355,8 +355,21 @@ struct mthca_dev {
 	spinlock_t            sm_lock;
 };
 
-#define mthca_dbg(mdev, format, arg...) \
-	dev_dbg(&mdev->pdev->dev, format, ## arg)
+#ifdef CONFIG_INFINIBAND_MTHCA_DEBUG
+extern int mthca_debug_level;
+
+#define mthca_dbg(mdev, format, arg...)					\
+	do {								\
+		if (mthca_debug_level)					\
+			dev_printk(KERN_DEBUG, &mdev->pdev->dev, format, ## arg); \
+	} while (0)
+
+#else /* CONFIG_INFINIBAND_MTHCA_DEBUG */
+
+#define mthca_dbg(mdev, format, arg...) do { (void) mdev; } while (0)
+
+#endif /* CONFIG_INFINIBAND_MTHCA_DEBUG */
+
 #define mthca_err(mdev, format, arg...) \
 	dev_err(&mdev->pdev->dev, format, ## arg)
 #define mthca_info(mdev, format, arg...) \
--- infiniband/hw/mthca/mthca_main.c	(revision 6101)
+++ infiniband/hw/mthca/mthca_main.c	(working copy)
@@ -52,6 +52,14 @@ MODULE_DESCRIPTION("Mellanox InfiniBand 
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_VERSION(DRV_VERSION);
 
+#ifdef CONFIG_INFINIBAND_MTHCA_DEBUG
+
+int mthca_debug_level = 0;
+module_param_named(debug_level, mthca_debug_level, int, 0644);
+MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0");
+
+#endif /* CONFIG_INFINIBAND_MTHCA_DEBUG */
+
 #ifdef CONFIG_PCI_MSI
 
 static int msi_x = 0;