From: Tvrtko Ursulin <tvrtko.ursu...@intel.com>

Currently the wait_for_atomic_us only allows for a millisecond
granularity which is not nice towards callers requesting small
micro-second waits.

Re-implement it so micro-second granularity is really supported
and not just in the name of the macro.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com>
---
Danger - this might break things which currently work by accident!
---
 drivers/gpu/drm/i915/intel_drv.h | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index f620023ed134..9e8a1202194c 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -63,10 +63,25 @@
        ret__;                                                          \
 })
 
+#define _wait_for_atomic(COND, US) ({ \
+       unsigned long end__; \
+       int ret__ = 0; \
+       get_cpu(); \
+       end__ = (local_clock() >> 10) + (US) + 1; \
+       while (!(COND)) { \
+               if (time_after((unsigned long)(local_clock() >> 10), end__)) { \
+                       ret__ = -ETIMEDOUT; \
+                       break; \
+               } \
+               cpu_relax(); \
+       } \
+       put_cpu(); \
+       ret__; \
+})
+
 #define wait_for(COND, MS) _wait_for(COND, MS, 1)
-#define wait_for_atomic(COND, MS) _wait_for(COND, MS, 0)
-#define wait_for_atomic_us(COND, US) _wait_for((COND), \
-                                              DIV_ROUND_UP((US), 1000), 0)
+#define wait_for_atomic(COND, MS) _wait_for_atomic(COND, (MS * 1000))
+#define wait_for_atomic_us(COND, US) _wait_for_atomic((COND), (US))
 
 #define KHz(x) (1000 * (x))
 #define MHz(x) KHz(1000 * (x))
-- 
1.9.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to