From mboxrd@z Thu Jan 1 00:00:00 1970 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=-14.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 BD528C32751 for ; Sat, 10 Aug 2019 04:49:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 891D6217D7 for ; Sat, 10 Aug 2019 04:49:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NGDK21aD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725865AbfHJEtY (ORCPT ); Sat, 10 Aug 2019 00:49:24 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:54098 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725372AbfHJEtY (ORCPT ); Sat, 10 Aug 2019 00:49:24 -0400 Received: by mail-wm1-f66.google.com with SMTP id 10so7513167wmp.3 for ; Fri, 09 Aug 2019 21:49:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ulCsjp9diZ2qriE+4Cg5mruQzjkUXFDOkC4POtPmsWA=; b=NGDK21aDRWljP1LXoWB7S8eE+O4vZ1sRPfi/6k40/DMPybzHr7mNWtTKcHG0jjthsc mV6aD6OTfwuTwiXPbaIBeM1dCZR8XWtXG9Czx1qYs8W/PMQ/6bDvj9e6BSjBqdwd8c1e 52QFjvRyIOsQ/+25KtWxSUB5hhxSKnG/Btjh34aUpDxqD9HwvhTUJBVFHi/UXJ1xCb1L nvhVcOSavxIpIEDynzALLMcV4JKDQ/2udmYf0Y6hLKloclHqeyBWRalaDV+/Cf6g/hrs VW537ESr+2HbYHILjzG/P5KZ7RuW6XQCcpErSc6c0vjbcHeOXh8OdXGznEDLtxbk9cT6 /zDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ulCsjp9diZ2qriE+4Cg5mruQzjkUXFDOkC4POtPmsWA=; b=j34tGst29O84GJAsV0wyzjmodfFXBAlOn0hnYnLU1FQA3qtf1LloD8XgpeAChNzCOd ip0on6dNHvF6CjnwY3e5tGjMf7CUjUDanZPI28ua2Lf7A1wfajycn5xUmJOh7XTzo9Aq rIH/03x4xy8nN7hdOdY70zKnIWxJw+lUOSnWdY0guSKdcdM/WTb2s6nTrl7YggXC9Tbv LtZh5A4Hgo49QizZBOAZsqagdi9UYaHvoon7mPsYdk+2VfEHZIM3h4WaZOP051X1Nk5R mkEhZ2NKzgAzeLPMJhaI30C9WbJPipluuzMxIPcD2OMtz824+2zpWVivr4rJXaYPBuAk sPAg== X-Gm-Message-State: APjAAAX3LMY3Z1Xc26u2AIqfDg8WwxklT/LGSMrRlfA/L0MJJd4waKQb 27l30nHlgRonl1+MrDqxwwQ= X-Google-Smtp-Source: APXvYqzmsiCROnIJE2KU/ceUpPoCJ5gdssn6Ej3YVxoCbp7xgJXDFAogI097PejjQ27EpheLWUvANQ== X-Received: by 2002:a7b:c310:: with SMTP id k16mr13781272wmj.133.1565412561667; Fri, 09 Aug 2019 21:49:21 -0700 (PDT) Received: from localhost.localdomain ([2a01:4f8:222:2f1b::2]) by smtp.gmail.com with ESMTPSA id x20sm218826181wrg.10.2019.08.09.21.49.20 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 09 Aug 2019 21:49:20 -0700 (PDT) From: Nathan Chancellor To: Sudeep Holla Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Nathan Chancellor Subject: [PATCH] firmware: arm_scmi: Eliminate local db variable in SCMI_PERF_FC_RING_DB Date: Fri, 9 Aug 2019 21:49:10 -0700 Message-Id: <20190810044910.114015-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.23.0.rc2 MIME-Version: 1.0 X-Patchwork-Bot: notify Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org clang warns four times: drivers/firmware/arm_scmi/perf.c:320:24: warning: variable 'db' is uninitialized when used within its own initialization [-Wuninitialized] SCMI_PERF_FC_RING_DB(db, 64); ~~~~~~~~~~~~~~~~~~~~~^~~~~~~ drivers/firmware/arm_scmi/perf.c:300:31: note: expanded from macro 'SCMI_PERF_FC_RING_DB' struct scmi_fc_db_info *db = doorbell; \ ~~ ^~~~~~~~ This happens because the doorbell identifier becomes db after preprocessing: if (db->width == 1) do { u8 val = 0; struct scmi_fc_db_info *db = db; if (db->mask) val = ioread8(db->addr) & db->mask; iowrite8((u8)db->set | val, db->addr); } while (0); We could swap the doorbell and db identifiers within the macro and that would resolve the issue; however, there doesn't appear to be a good reason for having two copies of the same variable. Eliminate the one in the do while loop to prevent this warning and make the code clearer. Fixes: 8f12cbcb6abc ("firmware: arm_scmi: Make use SCMI v2.0 fastchannel for performance protocol") Link: https://github.com/ClangBuiltLinux/linux/issues/635 Signed-off-by: Nathan Chancellor --- drivers/firmware/arm_scmi/perf.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c index 2c5201c8354c..ab946ef6b914 100644 --- a/drivers/firmware/arm_scmi/perf.c +++ b/drivers/firmware/arm_scmi/perf.c @@ -294,10 +294,9 @@ scmi_perf_describe_levels_get(const struct scmi_handle *handle, u32 domain, return ret; } -#define SCMI_PERF_FC_RING_DB(doorbell, w) \ +#define SCMI_PERF_FC_RING_DB(db, w) \ do { \ u##w val = 0; \ - struct scmi_fc_db_info *db = doorbell; \ \ if (db->mask) \ val = ioread##w(db->addr) & db->mask; \ -- 2.23.0.rc2