drm/i915: Allow configuring default request expiry via modparam

Module parameter is added (request_timeout_ms) to allow configuring the
default request/fence expiry.

Default value is inherited from CONFIG_DRM_I915_REQUEST_TIMEOUT.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-8-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/gem/i915_gem_context.c

@@ -815,11 +815,12 @@ static void __set_default_fence_expiry(struct i915_gem_context *ctx)
 	struct drm_i915_private *i915 = ctx->i915;
 	int ret;
 
-	if (!IS_ACTIVE(CONFIG_DRM_I915_REQUEST_TIMEOUT))
+	if (!IS_ACTIVE(CONFIG_DRM_I915_REQUEST_TIMEOUT) ||
+	    !i915->params.request_timeout_ms)
 		return;
 
 	/* Default expiry for user fences. */
-	ret = __set_watchdog(ctx, CONFIG_DRM_I915_REQUEST_TIMEOUT * 1000);
+	ret = __set_watchdog(ctx, i915->params.request_timeout_ms * 1000);
 	if (ret)
 		drm_notice(&i915->drm,
 			   "Failed to configure default fence expiry! (%d)",

drivers/gpu/drm/i915/i915_params.c

@@ -197,6 +197,11 @@ i915_param_named_unsafe(fake_lmem_start, ulong, 0400,
 	"Fake LMEM start offset (default: 0)");
 #endif
 
+#if CONFIG_DRM_I915_REQUEST_TIMEOUT
+i915_param_named_unsafe(request_timeout_ms, uint, 0600,
+			"Default request/fence/batch buffer expiration timeout.");
+#endif
+
 static __always_inline void _print_param(struct drm_printer *p,
 					 const char *name,
 					 const char *type,

drivers/gpu/drm/i915/i915_params.h

@@ -72,6 +72,7 @@ struct drm_printer;
 	param(int, enable_dpcd_backlight, -1, 0600) \
 	param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE, 0400) \
 	param(unsigned long, fake_lmem_start, 0, 0400) \
+	param(unsigned int, request_timeout_ms, CONFIG_DRM_I915_REQUEST_TIMEOUT, 0600) \
 	/* leave bools at the end to not create holes */ \
 	param(bool, enable_hangcheck, true, 0600) \
 	param(bool, load_detect_test, false, 0600) \