From patchwork Tue Jul 18 21:44:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 13317805 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BEC56EB64DC for ; Tue, 18 Jul 2023 21:44:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 12EC510E3C6; Tue, 18 Jul 2023 21:44:45 +0000 (UTC) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by gabe.freedesktop.org (Postfix) with ESMTPS id DDA9810E3C6; Tue, 18 Jul 2023 21:44:42 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7C24B60DC4; Tue, 18 Jul 2023 21:44:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2EC22C433C9; Tue, 18 Jul 2023 21:44:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689716680; bh=jWlvcID35qyNtU9PJLzd4/sdaK/gJ+Q9QVB2184F8e0=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=HSREdwlEhnf12riGluN+bX8K25XBDWkXzBk08230Uw3n9jT41cjujJ9mbE2PGnINJ 6TCWl5/6q6mvPahzB0nR6xzKza6gJBuHAGlcO3btWxTKEjDdsf98pBHKaoKWBomCV2 vc+A9XtkMIPZfgJRREPHb3zbDYnKo1bVhT29joO+MUvtXrMy3XYJBuqvGg9GstPVPw 9LvrJcCcDpaJuWTDVaw5071/gFf751dDNhEYxjiWBwvIwzMhk1rg0+ltRQo7zw8Uiq MlhJ6TOkq4wQUH6DNwI0vQs86rZR0My7XaTMV/KRq1HYzKdEZikbVXM8Z/jlTMbuZJ VcWdD2X2QLi8w== From: Nathan Chancellor Date: Tue, 18 Jul 2023 14:44:19 -0700 MIME-Version: 1.0 Message-Id: <20230718-nsecs_to_jiffies_timeout-constant-logical-operand-v1-1-36ed8fc8faea@kernel.org> References: <20230718-nsecs_to_jiffies_timeout-constant-logical-operand-v1-0-36ed8fc8faea@kernel.org> In-Reply-To: <20230718-nsecs_to_jiffies_timeout-constant-logical-operand-v1-0-36ed8fc8faea@kernel.org> To: jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, tvrtko.ursulin@linux.intel.com, emma@anholt.net, mwen@igalia.com X-Mailer: b4 0.13-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1710; i=nathan@kernel.org; h=from:subject:message-id; bh=jWlvcID35qyNtU9PJLzd4/sdaK/gJ+Q9QVB2184F8e0=; b=owGbwMvMwCEmm602sfCA1DTG02pJDCnb2Y/1CLp6mx1bP2HZyv8yZXx127Wn9qckXdwVVrNLz cxTrIe7o5SFQYyDQVZMkaX6sepxQ8M5ZxlvnJoEM4eVCWQIAxenAExk1gxGhpVVB97faX9o5LDl VFn2pUnKci65Hbw2Lxee4k/zzfK/x8PwP67nxtZwvWVXDv61de1WurA2nY//fN7T3onsm/ovNVQ lMwAA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 Subject: [Intel-gfx] [PATCH 1/2] drm/v3d: Avoid -Wconstant-logical-operand in nsecs_to_jiffies_timeout() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: trix@redhat.com, intel-gfx@lists.freedesktop.org, llvm@lists.linux.dev, ndesaulniers@google.com, patches@lists.linux.dev, dri-devel@lists.freedesktop.org, Nathan Chancellor , justinstitt@google.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" A proposed update to clang's -Wconstant-logical-operand to warn when the left hand side is a constant shows the following instance in nsecs_to_jiffies_timeout() when NSEC_PER_SEC is not a multiple of HZ, such as CONFIG_HZ=300: In file included from drivers/gpu/drm/v3d/v3d_debugfs.c:12: drivers/gpu/drm/v3d/v3d_drv.h:343:24: warning: use of logical '&&' with constant operand [-Wconstant-logical-operand] 343 | if (NSEC_PER_SEC % HZ && | ~~~~~~~~~~~~~~~~~ ^ drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: use '&' for a bitwise operation 343 | if (NSEC_PER_SEC % HZ && | ^~ | & drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: remove constant to silence this warning 1 warning generated. Turn this into an explicit comparison against zero to make the expression a boolean to make it clear this should be a logical check, not a bitwise one. Link: https://reviews.llvm.org/D142609 Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Reviewed-by: Maíra Canal --- drivers/gpu/drm/v3d/v3d_drv.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h index b74b1351bfc8..7f664a4b2a75 100644 --- a/drivers/gpu/drm/v3d/v3d_drv.h +++ b/drivers/gpu/drm/v3d/v3d_drv.h @@ -340,7 +340,7 @@ struct v3d_submit_ext { static inline unsigned long nsecs_to_jiffies_timeout(const u64 n) { /* nsecs_to_jiffies64() does not guard against overflow */ - if (NSEC_PER_SEC % HZ && + if ((NSEC_PER_SEC % HZ) != 0 && div_u64(n, NSEC_PER_SEC) >= MAX_JIFFY_OFFSET / HZ) return MAX_JIFFY_OFFSET;