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 1D53134041C; Wed, 20 May 2026 16:40:35 +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=1779295236; cv=none; b=Dlw96F5+2dLVcLKstieuxGaOO4pnGLabK6dbIYynkYE7OSZknd85bSg6CWV3buzwlKy4jC6FpJZiTey2+yXXe/tkZs1KBMWM/cAtaPBc6pmcLBnxswO4dJec+067tNQVKFgcDRnICAcLZiHBOLzAvfA+DpGOPmWYzmNKwMwFwz8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779295236; c=relaxed/simple; bh=Q3i36q1kgRsG7cJLuy9/nu9RQSWCpO9t7BkX9jixEFI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NSzUSzcPp/dy1EYOzhA253YqPowj5nsTtw0Xe2Yv30QW1sof6QCJUWPTU86yOhEzwEDvOeIeVri1zioE1hbULtmEyrWbJdupCvfM50XYH14lEaRT0RDnVB+/vvalnN6BPKXZnCHz4Sf3mPIZk4jftlJvVMWnvE2Y2CGXQ3FrkXM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NFsopgd9; 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="NFsopgd9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 813141F000E9; Wed, 20 May 2026 16:40:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779295235; bh=5nmiPH7L1md3w0OrDWAVa3Z0CAhFvWAVVfvdYxJ9uyI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NFsopgd9d+bXJczTR2VwVelg9hYZqsl1c0hPNLbpP5G+CqFRCuA7X1UiJWnzXHfln 0Ek7gaGaB50LDET2zAcgsON+tPXorEApVYSB34mNE2HCkycPgf53/8lvuP6nq4QcIN ND0f6/5TqQyPhaZgpqWdU/MrkaJVtC8wSso8m0jQ= 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 7.0 0302/1146] fbdev: matroxfb: Mark variable with __maybe_unused to avoid W=1 build break Date: Wed, 20 May 2026 18:09:12 +0200 Message-ID: <20260520162155.043530322@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162148.390695140@linuxfoundation.org> References: <20260520162148.390695140@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.0-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 e2c1478aa47f9..6a08f78cd1acb 100644 --- a/drivers/video/fbdev/matrox/g450_pll.c +++ b/drivers/video/fbdev/matrox/g450_pll.c @@ -409,7 +409,7 @@ 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