drm/i915/guc: Default to non-verbose GuC logging

Now that we've decoupled logging from relay, GuC log level is only
controlling the GuC behavior - there shouldn't be any impact on i915
behaviour. We're only going to see a single extra interrupt when log
will get half full.
That, and the fact that we're seeing igt/gem_exec_nop/basic-series
failing with non-verbose logging being disabled.

v2: Bring back the "auto" guc_log_level, now that we fixed the log

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180319095348.9716-11-michal.winiarski@intel.com

drivers/gpu/drm/i915/i915_params.h

@@ -48,7 +48,7 @@ struct drm_printer;
 	param(int, enable_ips, 1) \
 	param(int, invert_brightness, 0) \
 	param(int, enable_guc, 0) \
-	param(int, guc_log_level, 0) \
+	param(int, guc_log_level, -1) \
 	param(char *, guc_firmware_path, NULL) \
 	param(char *, huc_firmware_path, NULL) \
 	param(int, mmio_debug, 0) \

drivers/gpu/drm/i915/intel_uc.c

@@ -69,7 +69,7 @@ static int __get_platform_enable_guc(struct drm_i915_private *dev_priv)
 
 static int __get_default_guc_log_level(struct drm_i915_private *dev_priv)
 {
-	int guc_log_level = 0; /* disabled */
+	int guc_log_level = 1; /* non-verbose */
 
 	/* Enable if we're running on platform with GuC and debug config */
 	if (HAS_GUC(dev_priv) && intel_uc_is_using_guc() &&