From patchwork Tue Oct 27 13:48:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 290112 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3578C55178 for ; Tue, 27 Oct 2020 14:12:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 711DD22263 for ; Tue, 27 Oct 2020 14:12:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603807942; bh=gs572yzi9DtUTqIEsOp/fXLzap33LPim28JRC4DjSJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Eqy/ozb2/xuaV034+eJ78qLt6KueTHlq49+3uGS0iDx6NiP36LxiL/4maURX8KXct YyQXpuNtgbpd/A91aPGLnoqSgKeuwx9m+at98J9n12H3CDWGIBT1yucRXWAlpZtNLU Y2ewE7tojAHZ3nwmNIF0SLbVJkXU+/sfqIOiQBzI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1743972AbgJ0OMV (ORCPT ); Tue, 27 Oct 2020 10:12:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:59532 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755732AbgJ0OKo (ORCPT ); Tue, 27 Oct 2020 10:10:44 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 97D3D2072D; Tue, 27 Oct 2020 14:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603807843; bh=gs572yzi9DtUTqIEsOp/fXLzap33LPim28JRC4DjSJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dpdCfDGuVdygjmn0h6B5g1KsWrW2dZ0wMYyQ1+yAPwe2QItjeWfZtGRo9ktyUUjiK nWyAmEh0+3n7je3Hpvpjlkgp7pbMjCH2J+xmCQX/nL+zEhJF5n9VoPKe/oH/Srz6sb Ik1h06qdjoxuS0F9Fdu1FSY5Vr/3UWLQM69gGKx8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Daniel Vetter , Jani Nikula , Bartlomiej Zolnierkiewicz , Sasha Levin Subject: [PATCH 4.14 061/191] video: fbdev: vga16fb: fix setting of pixclock because a pass-by-value error Date: Tue, 27 Oct 2020 14:48:36 +0100 Message-Id: <20201027134912.665890201@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027134909.701581493@linuxfoundation.org> References: <20201027134909.701581493@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Colin Ian King [ Upstream commit c72fab81ceaa54408b827a2f0486d9a0f4be34cf ] The pixclock is being set locally because it is being passed as a pass-by-value argument rather than pass-by-reference, so the computed pixclock is never being set in var->pixclock. Fix this by passing by reference. [This dates back to 2002, I found the offending commit from the git history git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git ] Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Cc: Daniel Vetter Cc: Jani Nikula [b.zolnierkie: minor patch summary fixup] [b.zolnierkie: removed "Fixes:" tag (not in upstream tree)] Signed-off-by: Bartlomiej Zolnierkiewicz Link: https://patchwork.freedesktop.org/patch/msgid/20200723170227.996229-1-colin.king@canonical.com Signed-off-by: Sasha Levin --- drivers/video/fbdev/vga16fb.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/video/fbdev/vga16fb.c b/drivers/video/fbdev/vga16fb.c index ee6957a799bb6..aea8fd85cbf70 100644 --- a/drivers/video/fbdev/vga16fb.c +++ b/drivers/video/fbdev/vga16fb.c @@ -243,7 +243,7 @@ static void vga16fb_update_fix(struct fb_info *info) } static void vga16fb_clock_chip(struct vga16fb_par *par, - unsigned int pixclock, + unsigned int *pixclock, const struct fb_info *info, int mul, int div) { @@ -259,14 +259,14 @@ static void vga16fb_clock_chip(struct vga16fb_par *par, { 0 /* bad */, 0x00, 0x00}}; int err; - pixclock = (pixclock * mul) / div; + *pixclock = (*pixclock * mul) / div; best = vgaclocks; - err = pixclock - best->pixclock; + err = *pixclock - best->pixclock; if (err < 0) err = -err; for (ptr = vgaclocks + 1; ptr->pixclock; ptr++) { int tmp; - tmp = pixclock - ptr->pixclock; + tmp = *pixclock - ptr->pixclock; if (tmp < 0) tmp = -tmp; if (tmp < err) { err = tmp; @@ -275,7 +275,7 @@ static void vga16fb_clock_chip(struct vga16fb_par *par, } par->misc |= best->misc; par->clkdiv = best->seq_clock_mode; - pixclock = (best->pixclock * div) / mul; + *pixclock = (best->pixclock * div) / mul; } #define FAIL(X) return -EINVAL @@ -497,10 +497,10 @@ static int vga16fb_check_var(struct fb_var_screeninfo *var, if (mode & MODE_8BPP) /* pixel clock == vga clock / 2 */ - vga16fb_clock_chip(par, var->pixclock, info, 1, 2); + vga16fb_clock_chip(par, &var->pixclock, info, 1, 2); else /* pixel clock == vga clock */ - vga16fb_clock_chip(par, var->pixclock, info, 1, 1); + vga16fb_clock_chip(par, &var->pixclock, info, 1, 1); var->red.offset = var->green.offset = var->blue.offset = var->transp.offset = 0;