From: Nathan Chancellor nathan@kernel.org
stable inclusion from stable-v5.10.92 commit 66d21c005d9beaf874e466d63538ed37aa153c5e bugzilla: 186193 https://gitee.com/openeuler/kernel/issues/I53108
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 2e70570656adfe1c5d9a29940faa348d5f132199 upstream.
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-natha... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- 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 1f23cb6ece58..e51ca7ca0a2a 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3044,9 +3044,9 @@ 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;