A new warning in clang points out a place in this file where a bitwise
OR is being used with boolean types:

drivers/gpu/drm/i915/intel_pm.c:3066:12: warning: use of bitwise '|' with 
boolean operands [-Wbitwise-instead-of-logical]
        changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 
12) |
                  
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This construct is intentional, as it allows every one of the calls to
ilk_increase_wm_latency() to occur (instead of short circuiting with
logical OR) while still caring about the result of each call.

To make this clearer to the compiler, use the '|=' operator to assign
the result of each ilk_increase_wm_latency() call to changed, which
keeps the meaning of the code the same but makes it obvious that every
one of these calls is expected to happen.

Link: https://github.com/ClangBuiltLinux/linux/issues/1473
Reported-by: Nick Desaulniers <ndesaulni...@google.com>
Signed-off-by: Nathan Chancellor <nat...@kernel.org>
---
 drivers/gpu/drm/i915/intel_pm.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f90fe39cf8ca..aaa3a0998e4c 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3050,9 +3050,9 @@ static void snb_wm_latency_quirk(struct drm_i915_private 
*dev_priv)
         * The BIOS provided WM memory latency values are often
         * inadequate for high resolution displays. Adjust them.
         */
-       changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 
12) |
-               ilk_increase_wm_latency(dev_priv, dev_priv->wm.spr_latency, 12) 
|
-               ilk_increase_wm_latency(dev_priv, dev_priv->wm.cur_latency, 12);
+       changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 
12);
+       changed |= ilk_increase_wm_latency(dev_priv, dev_priv->wm.spr_latency, 
12);
+       changed |= ilk_increase_wm_latency(dev_priv, dev_priv->wm.cur_latency, 
12);
 
        if (!changed)
                return;

base-commit: d73b17465d6da0a94bc0fcc86b150e1e923e8f71
-- 
2.33.1.637.gf443b226ca

Reply via email to