drm/i915: Avoid bitwise vs logical OR warning in snb_wm_latency_quirk()
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 <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Dávid Bolvanský <david.bolvansky@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014211916.3550122-1-nathan@kernel.org
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f90fe39..aaa3a09 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;