This is a note to let you know that I've just added the patch titled drm/i915: Avoid bitwise vs logical OR warning in snb_wm_latency_quirk() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-i915-avoid-bitwise-vs-logical-or-warning-in-snb_wm_latency_quirk.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 2e70570656adfe1c5d9a29940faa348d5f132199 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor <nathan@xxxxxxxxxx> Date: Thu, 14 Oct 2021 14:19:16 -0700 Subject: drm/i915: Avoid bitwise vs logical OR warning in snb_wm_latency_quirk() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Nathan Chancellor <nathan@xxxxxxxxxx> 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@xxxxxxxxxx> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Suggested-by: Dávid Bolvanský <david.bolvansky@xxxxxxxxx> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20211014211916.3550122-1-nathan@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_pm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2274,9 +2274,9 @@ static void snb_wm_latency_quirk(struct * 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; Patches currently in stable-queue which might be from nathan@xxxxxxxxxx are queue-4.9/staging-wlan-ng-avoid-bitwise-vs-logical-or-warning-in-hfa384x_usb_throttlefn.patch queue-4.9/drm-i915-avoid-bitwise-vs-logical-or-warning-in-snb_wm_latency_quirk.patch