From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederic Chen Subject: Re: [RFC PATCH V1 6/6] platform: mtk-isp: Add Mediatek DIP driver Date: Tue, 11 Jun 2019 16:48:06 +0800 Message-ID: <1560242886.23799.13.camel@mtksdccf07> References: <20190417104511.21514-1-frederic.chen@mediatek.com> <20190417104511.21514-7-frederic.chen@mediatek.com> <20190509094846.GA65444@google.com> <1558466055.15388.342.camel@mtksdccf07> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1558466055.15388.342.camel@mtksdccf07> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Tomasz Figa Cc: shik@chromium.org, devicetree@vger.kernel.org, Sean.Cheng@mediatek.com, laurent.pinchart+renesas@ideasonboard.com, Rynn.Wu@mediatek.com, srv_heupstream@mediatek.com, holmes.chiou@mediatek.com, suleiman@chromium.org, Jerry-ch.Chen@mediatek.com, jungo.lin@mediatek.com, sj.huang@mediatek.com, yuzhao@chromium.org, linux-mediatek@lists.infradead.org, zwisler@chromium.org, matthias.bgg@gmail.com, christie.yu@mediatek.com, mchehab@kernel.org, hans.verkuil@cisco.com, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org List-Id: devicetree@vger.kernel.org Dear Tomasz, I'd like to elaborate more about the tuning_data.va. Would you like to give us some advice about our improvement proposal inline? Thank you very much. On Wed, 2019-05-22 at 03:14 +0800, Frederic Chen wrote: > Dear Tomasz, > > I appreciate your comment. It is very helpful for us. > > > > > diff --git a/drivers/media/platform/mtk-isp/isp_50/dip/mtk_dip-sys.c b/drivers/media/platform/mtk-isp/isp_50/dip/mtk_dip-sys.c > > > new file mode 100644 > > > index 000000000000..54d2b5f5b802 > > > --- /dev/null > > > +++ b/drivers/media/platform/mtk-isp/isp_50/dip/mtk_dip-sys.c > > > @@ -0,0 +1,1384 @@ [snip] > > > +static void dip_submit_worker(struct work_struct *work) > > > +{ > > > + struct mtk_dip_hw_submit_work *dip_submit_work = > > > + container_of(work, struct mtk_dip_hw_submit_work, frame_work); > > > + struct mtk_dip_hw *dip_hw = dip_submit_work->dip_hw; > > > + struct mtk_dip_dev *dip_dev = mtk_dip_hw_to_dev(dip_hw); > > > + struct mtk_dip_hw_work *dip_work; > > > + struct mtk_dip_hw_subframe *buf; > > > + u32 len, num; > > > + int ret; > > > + > > > + num = atomic_read(&dip_hw->num_composing); > > > + > > > + mutex_lock(&dip_hw->dip_worklist.queuelock); > > > + dip_work = list_first_entry(&dip_hw->dip_worklist.queue, [snip] > > > + > > > + if (dip_work->frameparams.tuning_data.pa == 0) { > > > + dev_dbg(&dip_dev->pdev->dev, > > > + "%s: frame_no(%d) has no tuning_data\n", > > > + __func__, dip_work->frameparams.frame_no); > > > + > > > + memcpy(&dip_work->frameparams.tuning_data, > > > + &buf->tuning_buf, sizeof(buf->tuning_buf)); > > > > Ditto. > > > > I got it. > > > > + memset((char *)buf->tuning_buf.va, 0, DIP_TUNING_SZ); > > > > Ditto. > > I got it. > > > > > > + /* > > > + * When user enqueued without tuning buffer, > > > + * it would use driver internal buffer. > > > + * So, tuning_data.va should be 0 > > > + */ > > > + dip_work->frameparams.tuning_data.va = 0; > > > > I don't understand this. We just zeroed the buffer via this kernel VA few > > lines above, so why would it have to be set to 0? > > > > I will remove this unnecessary line. > > > > + } After confirming the firmware part, I found that we use this field (tuning_data.va) to notify firmware if there is no tuning data from user. - frameparams.tuning_data.va is 0: use the default tuning data in SCP, but we still need to pass frameparams.tuning_data.pa because the buffer contains some working buffer required. - frameparams.tuning_data.va is not 0: the tuning data was passed from the user Since we should not pass cpu addres to SCP, could I rename tuning_data.va as tuning_data.cookie, and write a constant value to indicate if SCP should use its internal default setting or not here? For example, /* SCP uses tuning data passed from userspace*/ dip_work->frameparams.tuning_data.cookie = MTK_DIP_USER_TUNING_DATA; /* SCP uses internal tuning data */ dip_work->frameparams.tuning_data.cookie = MTK_DIP_DEFAULT_TUNING_DATA; > > > + > > > + dip_work->frameparams.drv_data = (u64)dip_hw; > > > > Passing kernel pointers to firmware? > > I will remove this line. > > > > > > + dip_work->frameparams.state = FRAME_STATE_COMPOSING; > > > + > > > + memcpy((void *)buf->frameparam.va, &dip_work->frameparams, > > > + sizeof(dip_work->frameparams)); > > > > There shouldn't be a need to type cast the pointer. > > > > I will fix it. > > > > + > > > + dip_send(dip_hw->vpu_pdev, SCP_IPI_DIP_FRAME, > > > + (void *)&dip_work->frameparams, > > [snip] Sincerely, Frederic Chen