drm/i915: Ensure that while(INREG()) are bounded (v2)

[mirror_ubuntu-bionic-kernel.git] / drivers / gpu / drm / i915 / intel_drv.h

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index c552b06e5d213bccaa3d31f025baa130f5d39fad..2a3eaaf64b24efd88a249dc8f325646f0b521eaa 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -32,6 +32,20 @@
 #include "drm_crtc.h"
 
 #include "drm_crtc_helper.h"
+
+#define wait_for(COND, MS, W) ({ \
+       unsigned long timeout__ = jiffies + msecs_to_jiffies(MS);       \
+       int ret__ = 0;                                                  \
+       while (! (COND)) {                                              \
+               if (time_after(jiffies, timeout__)) {                   \
+                       ret__ = -ETIMEDOUT;                             \
+                       break;                                          \
+               }                                                       \
+               if (W) msleep(W);                                       \
+       }                                                               \
+       ret__;                                                          \
+})
+
 /*
  * Display related stuff
  */