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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C129EE6425 for ; Fri, 15 Sep 2023 07:18:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232708AbjIOHS2 (ORCPT ); Fri, 15 Sep 2023 03:18:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232400AbjIOHS1 (ORCPT ); Fri, 15 Sep 2023 03:18:27 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7989EE0 for ; Fri, 15 Sep 2023 00:18:22 -0700 (PDT) Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by madras.collabora.co.uk (Postfix) with ESMTPSA id 82674660733F; Fri, 15 Sep 2023 08:18:20 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1694762301; bh=xtkvug0J6qipef4H7k8twsG7RHvOTDB4NQhN9bH6eLU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jWY7xzFzO5jwIXL4hrXYfzfQAdduHMs3LI5jgFXeFmsqBYJaU/OfPLqc09yjre3gK rKYqlAxWVtt6rfhkIxEsoUiIEYr7Ry6BjgSu4D/4ivNhwlvl5OEnLkxHAjLSnWPfV5 yGYF2BV3Hd32XteT+5gyo3vjufFcs2rP9Y0Fdfr45kNVvuuL+wGo4TUcCcxIW6T5Nq SG2xLpE3HeXl2BBvkjYSrw0RTTN9mRLa+G4yvxKiJ0xocFPtBx2ZqeJE5H15uWcSF5 m8uaojHf2y/nJChvaviwKzQkK+jhVKSMftmqUaGRnkEyrVi9eZNOdzCHvABrv8bTAh gqvENf9jx5xNg== Date: Fri, 15 Sep 2023 09:18:18 +0200 From: Boris Brezillon To: Dmitry Osipenko Cc: David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Christian =?UTF-8?B?S8O2bmln?= , Qiang Yu , Steven Price , Emma Anholt , Melissa Wen , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com, virtualization@lists.linux-foundation.org Subject: Re: [PATCH v17 11/18] drm/shmem-helper: Improve drm_gem_shmem_vmap_locked() error handling Message-ID: <20230915091818.1dd3d6ed@collabora.com> In-Reply-To: <20230914232721.408581-12-dmitry.osipenko@collabora.com> References: <20230914232721.408581-1-dmitry.osipenko@collabora.com> <20230914232721.408581-12-dmitry.osipenko@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 15 Sep 2023 02:27:14 +0300 Dmitry Osipenko wrote: > Remove error unwinding from drm_gem_shmem_vmap_locked() making error > paths consistent for both dmabuf and non-dmabuf cases and improving > readability of the code. Often it's preferred to do the explicit error > unwinding, but this multi-path function is an exception. > > Suggested-by: Boris Brezillon Actually, I suggested returning directly, but I hadn't noticed the debug message which you pointed in one of your replies. No longer sure it's a good idea to drop the error path, since it makes code addition more error-prone (pretty easy to forget the drm_gem_shmem_unpin_locked() in new error paths). > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 13 +++---------- > 1 file changed, 3 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index e1fcb5154209..8a8eab4d0332 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -334,7 +334,7 @@ int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, > struct iosys_map *map) > { > struct drm_gem_object *obj = &shmem->base; > - int ret = 0; > + int ret; > > if (obj->import_attach) { > ret = dma_buf_vmap(obj->import_attach->dmabuf, map); > @@ -357,6 +357,7 @@ int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, > shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, > VM_MAP, prot); > if (!shmem->vaddr) { > + drm_gem_shmem_unpin_locked(shmem); > ret = -ENOMEM; > } else { > iosys_map_set_vaddr(map, shmem->vaddr); > @@ -364,16 +365,8 @@ int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, > } > } > > - if (ret) { > + if (ret) > drm_dbg_kms(obj->dev, "Failed to vmap pages, error %d\n", ret); > - goto err_put_pages; > - } > - > - return 0; > - > -err_put_pages: > - if (!obj->import_attach) > - drm_gem_shmem_unpin_locked(shmem); > > return ret; > }