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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6141DC47087 for ; Fri, 28 May 2021 10:11:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 420F061404 for ; Fri, 28 May 2021 10:11:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236491AbhE1KNB convert rfc822-to-8bit (ORCPT ); Fri, 28 May 2021 06:13:01 -0400 Received: from aposti.net ([89.234.176.197]:52280 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236519AbhE1KMs (ORCPT ); Fri, 28 May 2021 06:12:48 -0400 Date: Fri, 28 May 2021 11:10:54 +0100 From: Paul Cercueil Subject: Re: [PATCH] drm: Fix for GEM buffers with write-combine memory To: Tomi Valkeinen Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , list@opendingux.net, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Message-Id: <6YATTQ.MSZ3AMJZMTBZ1@crapouillou.net> In-Reply-To: References: <26b5424a-ff4c-090b-a08f-0e3e32278180@ideasonboard.com> <20210527230334.151947-1-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tomi, Le ven., mai 28 2021 at 08:59:15 +0300, Tomi Valkeinen a écrit : > On 28/05/2021 02:03, Paul Cercueil wrote: >> The previous commit wrongly assumed that dma_mmap_wc() could be >> replaced >> by pgprot_writecombine() + dma_mmap_pages(). It did work on my setup, >> but did not work everywhere. >> >> Use dma_mmap_wc() when the buffer has the write-combine cache >> attribute, >> and dma_mmap_pages() when it has the non-coherent cache attribute. >> >> Signed-off-by: Paul Cercueil >> Reported-by: Tomi Valkeinen >> Fixes: cf8ccbc72d61 ("drm: Add support for GEM buffers backed by >> non-coherent memory") >> --- >> drivers/gpu/drm/drm_gem_cma_helper.c | 16 ++++++++++------ >> 1 file changed, 10 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c >> b/drivers/gpu/drm/drm_gem_cma_helper.c >> index 235c7a63da2b..4c3772651954 100644 >> --- a/drivers/gpu/drm/drm_gem_cma_helper.c >> +++ b/drivers/gpu/drm/drm_gem_cma_helper.c >> @@ -514,13 +514,17 @@ int drm_gem_cma_mmap(struct drm_gem_object >> *obj, struct vm_area_struct *vma) >>  cma_obj = to_drm_gem_cma_obj(obj); >> - vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); >> - if (!cma_obj->map_noncoherent) >> - vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); >> + if (cma_obj->map_noncoherent) { >> + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); >> + >> + ret = dma_mmap_pages(cma_obj->base.dev->dev, >> + vma, vma->vm_end - vma->vm_start, >> + virt_to_page(cma_obj->vaddr)); >> + } else { >> + ret = dma_mmap_wc(cma_obj->base.dev->dev, vma, cma_obj->vaddr, >> + cma_obj->paddr, vma->vm_end - vma->vm_start); >> - ret = dma_mmap_pages(cma_obj->base.dev->dev, >> - vma, vma->vm_end - vma->vm_start, >> - virt_to_page(cma_obj->vaddr)); >> + } >> if (ret) >> drm_gem_vm_close(vma); >>  > > Reviewed-by: Tomi Valkeinen > > and > > Tested-by: Tomi Valkeinen Thanks, I applied it now. > > Thanks! > > Btw, the kernel-doc for drm_gem_cma_create doesn't quite match, as it > says wc is always used. Alright, I'll send a patch later for this one too. Cheers, -Paul