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 CC7CCC4708C for ; Fri, 28 May 2021 10:11:13 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 9664561378 for ; Fri, 28 May 2021 10:11:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9664561378 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=crapouillou.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0551F6E4AE; Fri, 28 May 2021 10:11:13 +0000 (UTC) Received: from aposti.net (aposti.net [89.234.176.197]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2EC096E4AE for ; Fri, 28 May 2021 10:11:11 +0000 (UTC) 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 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: quoted-printable X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Thomas Zimmermann , list@opendingux.net Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Tomi, Le ven., mai 28 2021 at 08:59:15 +0300, Tomi Valkeinen=20 a =E9crit : > On 28/05/2021 02:03, Paul Cercueil wrote: >> The previous commit wrongly assumed that dma_mmap_wc() could be=20 >> replaced >> by pgprot_writecombine() + dma_mmap_pages(). It did work on my setup, >> but did not work everywhere. >>=20 >> Use dma_mmap_wc() when the buffer has the write-combine cache=20 >> attribute, >> and dma_mmap_pages() when it has the non-coherent cache attribute. >>=20 >> Signed-off-by: Paul Cercueil >> Reported-by: Tomi Valkeinen >> Fixes: cf8ccbc72d61 ("drm: Add support for GEM buffers backed by=20 >> non-coherent memory") >> --- >> drivers/gpu/drm/drm_gem_cma_helper.c | 16 ++++++++++------ >> 1 file changed, 10 insertions(+), 6 deletions(-) >>=20 >> diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c=20 >> 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=20 >> *obj, struct vm_area_struct *vma) >> =7F cma_obj =3D to_drm_gem_cma_obj(obj); >> =7F- vma->vm_page_prot =3D vm_get_page_prot(vma->vm_flags); >> - if (!cma_obj->map_noncoherent) >> - vma->vm_page_prot =3D pgprot_writecombine(vma->vm_page_prot); >> + if (cma_obj->map_noncoherent) { >> + vma->vm_page_prot =3D vm_get_page_prot(vma->vm_flags); >> + >> + ret =3D dma_mmap_pages(cma_obj->base.dev->dev, >> + vma, vma->vm_end - vma->vm_start, >> + virt_to_page(cma_obj->vaddr)); >> + } else { >> + ret =3D dma_mmap_wc(cma_obj->base.dev->dev, vma, cma_obj->vaddr, >> + cma_obj->paddr, vma->vm_end - vma->vm_start); >> =7F- ret =3D 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); >> =7F >=20 > Reviewed-by: Tomi Valkeinen >=20 > and >=20 > Tested-by: Tomi Valkeinen Thanks, I applied it now. >=20 > Thanks! >=20 > Btw, the kernel-doc for drm_gem_cma_create doesn't quite match, as it=20 > says wc is always used. Alright, I'll send a patch later for this one too. Cheers, -Paul