From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wr0-f170.google.com ([209.85.128.170]:36882 "EHLO mail-wr0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750967AbdHROmS (ORCPT ); Fri, 18 Aug 2017 10:42:18 -0400 Received: by mail-wr0-f170.google.com with SMTP id z91so63158207wrc.4 for ; Fri, 18 Aug 2017 07:42:17 -0700 (PDT) Subject: Re: [PATCH 1/7] media: vb2: add bidirectional flag in vb2_queue To: Hans Verkuil , Mauro Carvalho Chehab Cc: Pawel Osciak , Marek Szyprowski , Kyungmin Park , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org References: <20170818141606.4835-1-stanimir.varbanov@linaro.org> <20170818141606.4835-2-stanimir.varbanov@linaro.org> <89f1a78b-f136-7783-620d-25b92a7e5218@xs4all.nl> From: Stanimir Varbanov Message-ID: <6a14fac3-1fd0-15b7-a6bb-ad29032da504@linaro.org> Date: Fri, 18 Aug 2017 17:42:13 +0300 MIME-Version: 1.0 In-Reply-To: <89f1a78b-f136-7783-620d-25b92a7e5218@xs4all.nl> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Hans, On 08/18/2017 05:30 PM, Hans Verkuil wrote: > On 08/18/17 16:16, Stanimir Varbanov wrote: >> This change is intended to give to the v4l2 drivers a choice to >> change the default behavior of the v4l2-core DMA mapping direction >> from DMA_TO/FROM_DEVICE (depending on the buffer type CAPTURE or >> OUTPUT) to DMA_BIDIRECTIONAL during queue_init time. >> >> Initially the issue with DMA mapping direction has been found in >> Venus encoder driver where the hardware (firmware side) adds few >> lines padding on bottom of the image buffer, and the consequence >> is triggering of IOMMU protection faults. >> >> This will help supporting venus encoder (and probably other drivers >> in the future) which wants to map output type of buffers as >> read/write. >> >> Signed-off-by: Stanimir Varbanov >> --- >> drivers/media/v4l2-core/videobuf2-core.c | 17 ++++++++--------- >> include/media/videobuf2-core.h | 13 +++++++++++++ >> 2 files changed, 21 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c >> index 0924594989b4..cb115ba6a1d2 100644 >> --- a/drivers/media/v4l2-core/videobuf2-core.c >> +++ b/drivers/media/v4l2-core/videobuf2-core.c >> @@ -194,8 +194,6 @@ static void __enqueue_in_driver(struct vb2_buffer *vb); >> static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) >> { >> struct vb2_queue *q = vb->vb2_queue; >> - enum dma_data_direction dma_dir = >> - q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; >> void *mem_priv; >> int plane; >> int ret = -ENOMEM; >> @@ -209,7 +207,7 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) >> >> mem_priv = call_ptr_memop(vb, alloc, >> q->alloc_devs[plane] ? : q->dev, >> - q->dma_attrs, size, dma_dir, q->gfp_flags); >> + q->dma_attrs, size, q->dma_dir, q->gfp_flags); >> if (IS_ERR_OR_NULL(mem_priv)) { >> if (mem_priv) >> ret = PTR_ERR(mem_priv); >> @@ -978,8 +976,6 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb) >> void *mem_priv; >> unsigned int plane; >> int ret = 0; >> - enum dma_data_direction dma_dir = >> - q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; >> bool reacquired = vb->planes[0].mem_priv == NULL; >> >> memset(planes, 0, sizeof(planes[0]) * vb->num_planes); >> @@ -1030,7 +1026,7 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb) >> mem_priv = call_ptr_memop(vb, get_userptr, >> q->alloc_devs[plane] ? : q->dev, >> planes[plane].m.userptr, >> - planes[plane].length, dma_dir); >> + planes[plane].length, q->dma_dir); >> if (IS_ERR(mem_priv)) { >> dprintk(1, "failed acquiring userspace memory for plane %d\n", >> plane); >> @@ -1096,8 +1092,6 @@ static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb) >> void *mem_priv; >> unsigned int plane; >> int ret = 0; >> - enum dma_data_direction dma_dir = >> - q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; >> bool reacquired = vb->planes[0].mem_priv == NULL; >> >> memset(planes, 0, sizeof(planes[0]) * vb->num_planes); >> @@ -1156,7 +1150,7 @@ static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb) >> /* Acquire each plane's memory */ >> mem_priv = call_ptr_memop(vb, attach_dmabuf, >> q->alloc_devs[plane] ? : q->dev, >> - dbuf, planes[plane].length, dma_dir); >> + dbuf, planes[plane].length, q->dma_dir); >> if (IS_ERR(mem_priv)) { >> dprintk(1, "failed to attach dmabuf\n"); >> ret = PTR_ERR(mem_priv); >> @@ -2003,6 +1997,11 @@ int vb2_core_queue_init(struct vb2_queue *q) >> if (q->buf_struct_size == 0) >> q->buf_struct_size = sizeof(struct vb2_buffer); >> >> + if (q->bidirectional) >> + q->dma_dir = DMA_BIDIRECTIONAL; >> + else >> + q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; >> + >> return 0; >> } >> EXPORT_SYMBOL_GPL(vb2_core_queue_init); >> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h >> index cb97c224be73..ede09fff1de8 100644 >> --- a/include/media/videobuf2-core.h >> +++ b/include/media/videobuf2-core.h >> @@ -427,6 +427,17 @@ struct vb2_buf_ops { >> * @dev: device to use for the default allocation context if the driver >> * doesn't fill in the @alloc_devs array. >> * @dma_attrs: DMA attributes to use for the DMA. >> + * @dma_dir: DMA mapping direction. > > This one should be moved to the 'Private elements' section. This is set and used > by the vb2 core, drivers won't set this. > > Looks good otherwise. > Ah, correct, will fix that. Thanks! -- regards, Stan