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 18:07:28 +0800 Message-ID: <1560247648.23799.16.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> <1560242886.23799.13.camel@mtksdccf07> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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 Chen , devicetree@vger.kernel.org, Sean Cheng =?UTF-8?Q?=28=E9=84=AD=E6=98=87=E5=BC=98=29?= , Laurent Pinchart , Rynn Wu =?UTF-8?Q?=28=E5=90=B3=E8=82=B2=E6=81=A9=29?= , srv_heupstream , Holmes Chiou =?UTF-8?Q?=28=E9=82=B1=E6=8C=BA=29?= , suleiman@chromium.org, Jerry-ch Chen , Jungo Lin =?UTF-8?Q?=28=E6=9E=97=E6=98=8E=E4=BF=8A=29?= , Sj Huang , yuzhao@chromium.org, "moderated list:ARM/Mediatek SoC support" , zwisler@chromium.org, Matthias Brugger , Christie Yu =?UTF-8?Q?=28=E6=B8=B8=E9=9B=85=E6=83=A0=29?= , Mauro Carvalho Chehab List-Id: devicetree@vger.kernel.org Hi Tomasz, On Tue, 2019-06-11 at 17:59 +0900, Tomasz Figa wrote: > On Tue, Jun 11, 2019 at 5:48 PM Frederic Chen > wrote: > > > > 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; > > Perhaps we could just call it "present" and set to true or false? > Yes. I would like to use "present" here. Original: struct img_addr { u64 va; /* Used by Linux OS access */ u32 pa; /* Used by CM4 access */ u32 iova; /* Used by IOMMU HW access */ } __attribute__ ((__packed__)); struct img_ipi_frameparam { u32 index; u32 frame_no; u64 timestamp; u8 type; /* enum mdp_stream_type */ u8 state; u8 num_inputs; u8 num_outputs; u64 drv_data; struct img_input inputs[IMG_MAX_HW_INPUTS]; struct img_output outputs[IMG_MAX_HW_OUTPUTS]; struct img_addr tuning_data; struct img_addr subfrm_data; struct img_sw_addr config_data; struct img_sw_addr self_data; } __attribute__ ((__packed__)); Modified: struct tuning_buf { u8 present; u32 pa; /* Used by CM4 access */ u32 iova; /* Used by IOMMU HW access */ } __attribute__ ((__packed__)); struct img_ipi_frameparam { /* ... */ struct tuning_buf tuning_data; /* ... */ } __attribute__ ((__packed__)); > Best regards, > Tomasz Sincerely, Frederic Chen