From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 873303148DA; Sat, 30 May 2026 17:12:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780161145; cv=none; b=dWDD/gFfLXMfZAy3980Sim9ltzz68tIY5kbrzUyl6AtXk63BJ2riSRnMNPWFdpam7Ljo2SUdDfHCHnjhtXVUMJ9OmjoWNDGFAp8aQXu52DzcQJCofwiXYB6fuu8G6r4ThxjevH9qJU4YeVEFOPV/e5zggI25nnGv96b9q7yXz0A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780161145; c=relaxed/simple; bh=pb9394vX1NAEXOEiDzN41z/rGNtPq77ny+733Ccbgzc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X2oH87IEZAlXx0dDZb61h/QZ8Hb5BkFuhC/7LOSJZkT6t5CWT9+m/b3mvPFoCsLqt8+UORdZ81GMjfNIXPRijXaiNJH3fewhRP9M/vNGYUtn1eaLGJpsJMOYqlbxtIsnmn11wG2tILSV42CyqT02thFkbx1sMSMi83RBX7aqhjc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aLixAQbL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="aLixAQbL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C32E31F00893; Sat, 30 May 2026 17:12:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780161144; bh=pRqfJ52H2nxtHVg8BS2EpQnNKDinpKo1WQMc7H4htJk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aLixAQbLQfJ4ns/fJoDfye3zeW0LHXFqUV4V29TnYuf3dkYbQ5QHtaO3FSNPdWdGs JmQq/YgSbKZezEJLeO49upXun+jwRM3QE5r1SedRRlHu3kwbMQc6YkiEqevfIVdJHJ /DWa1JsP42Am/gK2jgOKd3/vwE+Nd3U0FuWwrmbM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andy Shevchenko , Jason Yan , Helge Deller , Sasha Levin Subject: [PATCH 6.1 508/969] fbdev: matroxfb: Mark variable with __maybe_unused to avoid W=1 build break Date: Sat, 30 May 2026 18:00:32 +0200 Message-ID: <20260530160314.359698678@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160300.485627683@linuxfoundation.org> References: <20260530160300.485627683@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Shevchenko [ Upstream commit caf6144053b4e1c815aa56afb54745a176f999df ] Clang is not happy about set but unused variable: drivers/video/fbdev/matrox/g450_pll.c:412:18: error: variable 'mnp' set but not used 412 | unsigned int mnp; | ^ 1 error generated. Since the commit 7b987887f97b ("video: fbdev: matroxfb: remove dead code and set but not used variable") the 'mnp' became unused, but eliminating that code might have side-effects. The question here is what should we do with 'mnp'? The easiest way out is just mark it with __maybe_unused which will shut the compiler up and won't change any possible IO flow. So does this change. A dive into the history of the driver: The problem was revealed when the #if 0 guarded code along with unused pixel_vco variable was removed. That code was introduced in the original commit 213d22146d1f ("[PATCH] (1/3) matroxfb for 2.5.3"). And then guarded in the commit 705e41f82988 ("matroxfb DVI updates: Handle DVI output on G450/G550. Powerdown unused portions of G450/G550 DAC. Split G450/G550 DAC from older DAC1064 handling. Modify PLL setting when both CRTCs use same pixel clocks."). NOTE: The two commits mentioned above pre-date Git era and available in history.git repository for archaeological purposes. Even without that guard the modern compilers may see that the pixel_vco wasn't ever used and seems a leftover after some debug or review made 25 years ago. The g450_mnp2vco() doesn't have any IO and as Jason said doesn't seem to have any side effects either than some unneeded CPU processing during runtime. I agree that's unlikely that timeout (or heating up the CPU) has any effect on the HW (GPU/display) functionality. Fixes: 7b987887f97b ("video: fbdev: matroxfb: remove dead code and set but not used variable") Signed-off-by: Andy Shevchenko Reviewed-by: Jason Yan Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- drivers/video/fbdev/matrox/g450_pll.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/matrox/g450_pll.c b/drivers/video/fbdev/matrox/g450_pll.c index ff8e321a22cef..b2d3f7328ea83 100644 --- a/drivers/video/fbdev/matrox/g450_pll.c +++ b/drivers/video/fbdev/matrox/g450_pll.c @@ -407,7 +407,7 @@ static int __g450_setclk(struct matrox_fb_info *minfo, unsigned int fout, case M_VIDEO_PLL: { u_int8_t tmp; - unsigned int mnp; + unsigned int mnp __maybe_unused; unsigned long flags; matroxfb_DAC_lock_irqsave(flags); -- 2.53.0