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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY autolearn=unavailable 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 6340EC4743F for ; Mon, 7 Jun 2021 20:57:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B2ED6121D for ; Mon, 7 Jun 2021 20:57:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230386AbhFGU7F (ORCPT ); Mon, 7 Jun 2021 16:59:05 -0400 Received: from smtprelay0219.hostedemail.com ([216.40.44.219]:46632 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S230333AbhFGU7C (ORCPT ); Mon, 7 Jun 2021 16:59:02 -0400 Received: from omf16.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay08.hostedemail.com (Postfix) with ESMTP id 06D02182CF670; Mon, 7 Jun 2021 20:57:10 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: joe@perches.com) by omf16.hostedemail.com (Postfix) with ESMTPA id 3303C255114; Mon, 7 Jun 2021 20:57:08 +0000 (UTC) Message-ID: <179e1e6a1c383650b65d73a4ea98d5e22c34e562.camel@perches.com> Subject: Re: [PATCH][next] drm/i915/gem: Fix fall-through warning for Clang From: Joe Perches To: "Gustavo A. R. Silva" , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Kees Cook Date: Mon, 07 Jun 2021 13:57:06 -0700 In-Reply-To: <20210607203229.GA60476@embeddedor> References: <20210607203229.GA60476@embeddedor> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspamout01 X-Rspamd-Queue-Id: 3303C255114 X-Stat-Signature: pgm14zeb35swy91hjkipde1pgsrpsfgb X-Session-Marker: 6A6F6540706572636865732E636F6D X-Session-ID: U2FsdGVkX19L9gsetg5NN1XIjN0ilmq/oYUJ5kbZDSw= X-HE-Tag: 1623099428-943858 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2021-06-07 at 15:32 -0500, Gustavo A. R. Silva wrote: > In preparation to enable -Wimplicit-fallthrough for Clang, fix a > warning by explicitly adding a fallthrough; statement. [] > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c [] > @@ -62,6 +62,7 @@ static void try_to_writeback(struct drm_i915_gem_object *obj, >   switch (obj->mm.madv) { >   case I915_MADV_DONTNEED: >   i915_gem_object_truncate(obj); > + fallthrough; >   case __I915_MADV_PURGED: >   return; >   } I think fallthrough to return is not particularly nice to follow. This is the current function: static void try_to_writeback(struct drm_i915_gem_object *obj, unsigned int flags) { switch (obj->mm.madv) { case I915_MADV_DONTNEED: i915_gem_object_truncate(obj); case __I915_MADV_PURGED: return; } if (flags & I915_SHRINK_WRITEBACK) i915_gem_object_writeback(obj); } One of these might be more typical: static void try_to_writeback(struct drm_i915_gem_object *obj, unsigned int flags) { switch (obj->mm.madv) { case I915_MADV_DONTNEED: i915_gem_object_truncate(obj); break; case __I915_MADV_PURGED: break; default: if (flags & I915_SHRINK_WRITEBACK) i915_gem_object_writeback(obj); break; } } or maybe: static void try_to_writeback(struct drm_i915_gem_object *obj, unsigned int flags) { switch (obj->mm.madv) { case I915_MADV_DONTNEED: i915_gem_object_truncate(obj); return; case __I915_MADV_PURGED: return; } if (flags & I915_SHRINK_WRITEBACK) i915_gem_object_writeback(obj); }