From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751711AbdJSHU6 (ORCPT ); Thu, 19 Oct 2017 03:20:58 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:48520 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751078AbdJSHUy (ORCPT ); Thu, 19 Oct 2017 03:20:54 -0400 X-Google-Smtp-Source: ABhQp+RuN7rhGz9U0WN+/xbnf0aGh+hvsX4VcdB2SBY/Q+3TcY9DUErnrP8fQ2cQvTttd/JRDIBTYYERyMf2CiVY6uY= MIME-Version: 1.0 In-Reply-To: <230ceb18-1d69-7fa8-acb0-c810094f8e50@xs4all.nl> References: <1507783506-3884-1-git-send-email-tharvey@gateworks.com> <1507783506-3884-4-git-send-email-tharvey@gateworks.com> <230ceb18-1d69-7fa8-acb0-c810094f8e50@xs4all.nl> From: Tim Harvey Date: Thu, 19 Oct 2017 00:20:51 -0700 Message-ID: Subject: Re: [PATCH v2 3/4] media: i2c: Add TDA1997x HDMI receiver driver To: Hans Verkuil Cc: linux-media , alsa-devel@alsa-project.org, "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Shawn Guo , Steve Longerbeam , Philipp Zabel , Hans Verkuil , Mauro Carvalho Chehab Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 18, 2017 at 5:04 AM, Hans Verkuil wrote: > Hi Tim, > > Here is my review of this v2: > > On 10/12/17 06:45, Tim Harvey wrote: >> Add support for the TDA1997x HDMI receivers. >> >> + >> +/* >> + * Video Input formats >> + */ >> +struct vhref_values { >> + u16 href_start; >> + u16 href_end; >> + u16 vref_f1_start; >> + u8 vref_f1_width; >> + u16 vref_f2_start; >> + u8 vref_f2_width; >> + u16 fieldref_f1_start; >> + u8 fieldPolarity; >> + u16 fieldref_f2_start; > > Since we don't support interlaced (yet) I'd just drop the 'f2' fields. > Ditto for fieldPolarity. > > Can't these href/vref values be calculated from the timings? > The values in this struct are used to configure the tda1997x VHREF timing generator in tda1997x_configure_input_resolution() for generating the video output bus timings so I can't really drop them unless I can calculate them. Let me look into this - should be possible. >> +}; >> + >> +/* parse an infoframe and do some sanity checks on it */ >> +static unsigned int >> +tda1997x_parse_infoframe(struct tda1997x_state *state, u16 addr) >> +{ >> + struct v4l2_subdev *sd = &state->sd; >> + union hdmi_infoframe frame; >> + u8 buffer[40]; >> + u8 reg; >> + int len, err; >> + >> + /* read data */ >> + len = io_readn(sd, addr, sizeof(buffer), buffer); >> + err = hdmi_infoframe_unpack(&frame, buffer); >> + if (err) { >> + v4l_err(state->client, >> + "failed parsing %d byte infoframe: 0x%04x/0x%02x\n", >> + len, addr, buffer[0]); >> + return err; >> + } >> + if (debug > 1) >> + hdmi_infoframe_log(KERN_INFO, &state->client->dev, &frame); >> + switch (frame.any.type) { >> + /* Audio InfoFrame: see HDMI spec 8.2.2 */ >> + case HDMI_INFOFRAME_TYPE_AUDIO: >> + /* sample rate */ >> + switch (frame.audio.sample_frequency) { >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_32000: >> + state->audio_samplerate = 32000; >> + break; >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_44100: >> + state->audio_samplerate = 44100; >> + break; >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_48000: >> + state->audio_samplerate = 48000; >> + break; >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_88200: >> + state->audio_samplerate = 88200; >> + break; >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_96000: >> + state->audio_samplerate = 96000; >> + break; >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_176400: >> + state->audio_samplerate = 176400; >> + break; >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_192000: >> + state->audio_samplerate = 192000; >> + break; >> + default: >> + case HDMI_AUDIO_SAMPLE_FREQUENCY_STREAM: >> + break; >> + } >> + >> + /* sample size */ >> + switch (frame.audio.sample_size) { >> + case HDMI_AUDIO_SAMPLE_SIZE_16: >> + state->audio_samplesize = 16; >> + break; >> + case HDMI_AUDIO_SAMPLE_SIZE_20: >> + state->audio_samplesize = 20; >> + break; >> + case HDMI_AUDIO_SAMPLE_SIZE_24: >> + state->audio_samplesize = 24; >> + break; >> + case HDMI_AUDIO_SAMPLE_SIZE_STREAM: >> + default: >> + break; >> + } >> + >> + /* Channel Count */ >> + state->audio_channels = frame.audio.channels; >> + if (frame.audio.channel_allocation && >> + frame.audio.channel_allocation != state->audio_ch_alloc) { >> + /* use the channel assignment from the infoframe */ >> + state->audio_ch_alloc = frame.audio.channel_allocation; >> + tda1997x_configure_audout(sd, state->audio_ch_alloc); >> + /* reset the audio FIFO */ >> + tda1997x_hdmi_info_reset(sd, RESET_AUDIO, false); >> + } >> + break; >> + >> + /* Source Product Descriptor information (SPD) */ >> + case HDMI_INFOFRAME_TYPE_SPD: >> + strncpy(frame.spd.vendor, state->vendor, >> + sizeof(frame.spd.vendor)); >> + strncpy(frame.spd.product, state->product, >> + sizeof(frame.spd.product)); >> + v4l_info(state->client, "Source Product Descriptor: %s %s\n", >> + state->vendor, state->product); > > Use hdmi_infoframe_log() for logging infoframes. ok - I will always call hdmi_infoframe_log() above and refrain from outputs that just repeat those details. > >> + break; >> + >> + /* Auxiliary Video information (AVI) InfoFrame: see HDMI spec 8.2.1 */ >> + case HDMI_INFOFRAME_TYPE_AVI: >> + state->colorspace = frame.avi.colorspace; >> + state->colorimetry = frame.avi.colorimetry; >> + /* >> + * If colorimetry not specified, conversion depends on res type: >> + * - SDTV: ITU601 for SD (480/576/240/288 line resolution) >> + * - HDTV: ITU709 for HD (720/1080 line resolution) >> + * - PC: sRGB >> + * see HDMI specification section 6.7 >> + */ >> + if ((state->colorspace == HDMI_COLORSPACE_YUV422 || >> + state->colorspace == HDMI_COLORSPACE_YUV444) && >> + (state->colorimetry == HDMI_COLORIMETRY_EXTENDED || >> + state->colorimetry == HDMI_COLORIMETRY_NONE)) { >> + switch (state->timings.bt.height) { >> + case 480: >> + case 576: >> + case 240: >> + case 288: >> + state->colorimetry = HDMI_COLORIMETRY_ITU_601; >> + break; >> + case 720: >> + case 1080: >> + state->colorimetry = HDMI_COLORIMETRY_ITU_709; >> + break; >> + default: >> + state->colorimetry = HDMI_COLORIMETRY_NONE; > > Missing break. > oops - thanks >> + } >> + } >> + v4l_dbg(1, debug, state->client, >> + "Colorspace=%d Colorimetry=%d\n", >> + state->colorspace, state->colorimetry); >> + >> + /* configure upsampler: 0=bypass 1=repeatchroma 2=interpolate */ >> + reg = io_read(sd, REG_PIX_REPEAT); >> + reg &= ~PIX_REPEAT_MASK_UP_SEL; >> + if (state->colorspace == HDMI_COLORSPACE_YUV422) >> + reg |= (PIX_REPEAT_CHROMA << PIX_REPEAT_SHIFT); >> + io_write(sd, REG_PIX_REPEAT, reg); >> + >> + /* ConfigurePixelRepeater: repeat n-times each pixel */ >> + reg = io_read(sd, REG_PIX_REPEAT); >> + reg &= ~PIX_REPEAT_MASK_REP; >> + reg |= frame.avi.pixel_repeat; >> + io_write(sd, REG_PIX_REPEAT, reg); >> + >> + /* configure the receiver with the new colorspace */ >> + tda1997x_configure_conv(sd, state->colorspace, >> + state->colorimetry); > > What I am missing here is handling of the RGB quantization range. > An HDMI receiver will typically send full range RGB or limited range YUV > to the SoC. The HDMI source can however send full or limited range RGB > or limited range YUV (full range YUV is theoretically possible, but nobody > does that). > isn't this quantization range a function of the colorspace and colorimetry dictated by the AVI infoframe? I'm taking these into consideration when setting up the conversion matrix in tda1997x_configure_conv(). > For a Full HD receiver the rules when receiving RGB video are as follows: > > If the EDID supports selectable RGB Quantization Range, then check if the > source explicitly sets the RGB quantization range in the AVI InfoFrame and > use that value. > > Otherwise fall back to the default rules: > > if VIC == 0, then expect full range RGB, otherwise expect limited range RGB. Are you referring to the video_code field of the AVI infoframe or vic from a vendor infoframe? > > It gets even more complicated with 4k video, but this is full HD only. > > In addition, you may also want to implement the V4L2_CID_DV_RX_RGB_RANGE control > to let userspace override the autodetection. I'll add that as an additional patch. Are there other V4L2_CID's that I should be adding here? > > RGB Quantization Range handling is *the* biggest headache for HDMI receivers. > > If you happen to attend the Embedded Linux Conference Europe in Prague next > week, then attend my presentation on HDMI 4k Video on the Wednesday for all > the reasons why this is so tricky. > >> + break; >> + default: >> + break; >> + } >> + return 0; >> +} >> + >> +static int tda1997x_query_dv_timings(struct v4l2_subdev *sd, >> + struct v4l2_dv_timings *timings) >> +{ >> + struct tda1997x_state *state = to_state(sd); >> + int ret; >> + >> + v4l_dbg(1, debug, state->client, "%s\n", __func__); >> + if (!timings) >> + return -EINVAL; >> + >> + memset(timings, 0, sizeof(struct v4l2_dv_timings)); >> + mutex_lock(&state->lock); >> + ret = tda1997x_detect_std(state); >> + if (ret) >> + goto error; >> + *timings = state->std->timings; >> + mutex_unlock(&state->lock); >> + return 0; >> + >> +error: >> + mutex_unlock(&state->lock); >> + return ret; > > This can be simplified: > > ret = tda1997x_detect_std(state); > if (!ret) > *timings = state->std->timings; > mutex_unlock(&state->lock); > return ret; > yes, will do >> +} >> + >> + >> +static int tda1997x_set_edid(struct v4l2_subdev *sd, struct v4l2_edid *edid) >> +{ >> + struct tda1997x_state *state = to_state(sd); >> + int i; >> + >> + v4l_dbg(1, debug, state->client, "%s pad=%d\n", __func__, edid->pad); >> + memset(edid->reserved, 0, sizeof(edid->reserved)); >> + >> + if (edid->start_block != 0) >> + return -EINVAL; >> + >> + if (edid->blocks == 0) { >> + state->edid.blocks = 0; >> + state->edid.present = 0; >> + tda1997x_manual_hpd(&state->sd, HPD_LOW_BP); >> + return 0; >> + } >> + >> + if (edid->blocks > 2) { >> + edid->blocks = 2; >> + return -E2BIG; >> + } >> + >> + /* write base EDID */ >> + for (i = 0; i < 128; i++) >> + io_write(sd, REG_EDID_IN_BYTE0 + i, edid->edid[i]); >> + >> + /* write CEA Extension */ >> + for (i = 0; i < 128; i++) >> + io_write(sd, REG_EDID_IN_BYTE128 + i, edid->edid[i+128]); >> + > > Before updating the EDID pull the HPD low. Afterwards pull it up again. > The minimum time the HPD should remain low is 100 ms. > ok - I will add a delayed work procedure to handle this. By the way, how do I get/set EDID on a v4l2-subdev? root@ventana:~# v4l2-ctl -d4 --set-edid=pad=0,type=hdmi CEA-861 Header IT Formats Underscanned: yes Audio: yes YCbCr 4:4:4: yes YCbCr 4:2:2: yes Speaker Allocation Data Block FL/FR: yes LFE: no FC: no RL/RR: no RC: no FLC/FRC: no RLC/RRC: no FLW/FRW: no FLH/FRH: no TC: no FCH: no HDMI Vendor-Specific Data Block Max TMDS Clock: 170 MHz Physical Address: 1.0.0.0 YCbCr 4:4:4 Deep Color: no 30-bit: no 36-bit: no 48-bit: no Graphics: yes Photo: no Cinema: no Game: no CEA-861 Video Capability Descriptor RGB Quantization Range: yes YCC Quantization Range: yes PT: Always Underscanned IT: Always Underscanned CE: Always Underscanned CEA-861 Colorimetry Data Block xvYCC 601: no xvYCC 709: no sYCC: no AdobeRGB: no AdobeYCC: no BT.2020 RGB: no BT.2020 YCC: no BT.2020 cYCC: no CEA-861 HDR Static Metadata Data Block SDR (Traditional Gamma): yes HDR (Traditional Gamma): no SMPTE 2084: no VIDIOC_S_EDID: failed: Inappropriate ioctl for device root@ventana:~# I'm also not clear how to run v4l2-compliance on a v4l2-subdev, so I just ran it on one of the video devs from the capture driver I'm linked to via media-ctl. >> + return 0; >> +} >> + >> +static int tda1997x_get_dv_timings_cap(struct v4l2_subdev *sd, >> + struct v4l2_dv_timings_cap *cap) >> +{ >> + *cap = tda1997x_dv_timings_cap; >> + return 0; >> +} >> + >> +static int tda1997x_enum_dv_timings(struct v4l2_subdev *sd, >> + struct v4l2_enum_dv_timings *timings) >> +{ >> + struct tda1997x_state *state = to_state(sd); >> + >> + return v4l2_enum_dv_timings_cap(timings, &tda1997x_dv_timings_cap, >> + tda1997x_check_dv_timings, state); >> +} >> + >> +static const struct v4l2_subdev_pad_ops tda1997x_pad_ops = { >> + .enum_mbus_code = tda1997x_enum_mbus_code, >> + .get_fmt = tda1997x_get_pad_format, >> + .set_fmt = tda1997x_set_pad_format, >> + .get_edid = tda1997x_get_edid, >> + .set_edid = tda1997x_set_edid, >> + .dv_timings_cap = tda1997x_get_dv_timings_cap, >> + .enum_dv_timings = tda1997x_enum_dv_timings, >> +}; >> + >> +/* ----------------------------------------------------------------------------- >> + * v4l2_subdev_core_ops >> + */ >> + >> +static int tda1997x_log_status(struct v4l2_subdev *sd) >> +{ >> + struct tda1997x_state *state = to_state(sd); >> + const struct v4l2_dv_timings *timings = &state->timings; >> + >> + v4l2_info(sd, "-----Signal status-----\n"); >> + if (!timings) { > > timings can never be NULL. oops - yes, this should be if (!state->std) to detect signal status > >> + v4l2_info(sd, "no signal\n"); >> + return 0; >> + } >> + v4l2_info(sd, "resolution: %dx%d%c@%dHz\n", >> + timings->bt.width, timings->bt.height, >> + timings->bt.interlaced ? 'i' : 'p', >> + state->fps); >> + v4l2_print_dv_timings(sd->name, "Detected format: ", >> + timings, true); >> + v4l2_info(sd, "colorspace: %d\n", state->colorspace); >> + v4l2_info(sd, "colorimetry: %d\n", state->colorimetry); >> + if (state->audio_channels) >> + v4l2_info(sd, "audio: %dch %dHz\n", state->audio_channels, >> + state->audio_samplerate); >> + else >> + v4l2_info(sd, "audio: none\n"); >> + v4l2_info(sd, "vendor: %s\n", state->vendor); >> + v4l2_info(sd, "product: %s\n", state->product); > > If at all possible you should log the received InfoFrames here (hdmi_infoframe_log). > Also whether an EDID is loaded or not and the HPD state. > > If the hardware supports 5V detection, then you should log that too. In that case > also implement support for the V4L2_CID_DV_RX_POWER_PRESENT control. > > Also any information on the signal detection (clock lock, sync lock(s), whatever). > > This all helps enormously when debugging problems. It's important to spend some > time on this function. The adv7604.c source might be a good place to look for > inspiration. ok - I will add what I can. I can't figure out how to use log-status on a subdev either: root@ventana:~# cat /sys/class/video4linux/v4l-subdev1/name tda19971 2-0048 root@ventana:~# v4l2-ctl -d /dev/v4l-subdev1 --log-status VIDIOC_QUERYCAP: failed: Inappropriate ioctl for device /dev/v4l-subdev1: not a v4l2 node > >> + >> + return 0; >> +} >> + >> + >> +static int tda1997x_core_init(struct v4l2_subdev *sd) >> +{ >> + struct tda1997x_state *state = to_state(sd); >> + struct tda1997x_platform_data *pdata = &state->pdata; >> + u8 reg; >> + int i; >> + >> + /* disable HPD */ >> + io_write(sd, REG_HPD_AUTO_CTRL, HPD_AUTO_HPD_UNSEL); >> + if (state->chip_revision == 0) { >> + io_write(sd, REG_MAN_SUS_HDMI_SEL, MAN_DIS_HDCP | MAN_RST_HDCP); >> + io_write(sd, REG_CGU_DBG_SEL, 1 << CGU_DBG_CLK_SEL_SHIFT); >> + } >> + >> + /* reset infoframe at end of start-up-sequencer */ >> + io_write(sd, REG_SUS_SET_RGB2, 0x06); >> + io_write(sd, REG_SUS_SET_RGB3, 0x06); >> + >> + /* Enable TMDS pull-ups */ >> + io_write(sd, REG_RT_MAN_CTRL, RT_MAN_CTRL_RT | >> + RT_MAN_CTRL_RT_B | RT_MAN_CTRL_RT_A); >> + >> + /* enable sync measurement timing */ >> + tda1997x_cec_write(sd, REG_PWR_CONTROL & 0xff, 0x04); >> + /* adjust CEC clock divider */ >> + tda1997x_cec_write(sd, REG_OSC_DIVIDER & 0xff, 0x03); >> + tda1997x_cec_write(sd, REG_EN_OSC_PERIOD_LSB & 0xff, 0xa0); >> + io_write(sd, REG_TIMER_D, 0x54); >> + /* enable power switch */ >> + reg = tda1997x_cec_read(sd, REG_CONTROL & 0xff); >> + reg |= 0x20; >> + tda1997x_cec_write(sd, REG_CONTROL & 0xff, reg); >> + mdelay(50); >> + >> + /* read the chip version */ >> + reg = io_read(sd, REG_VERSION); >> + /* get the chip configuration */ >> + reg = io_read(sd, REG_CMTP_REG10); >> + >> + /* enable interrupts we care about */ >> + io_write(sd, REG_INT_MASK_TOP, >> + INTERRUPT_HDCP | INTERRUPT_AUDIO | INTERRUPT_INFO | >> + INTERRUPT_RATE | INTERRUPT_SUS); >> + /* config_mtp,fmt,sus_end,sus_st */ >> + io_write(sd, REG_INT_MASK_SUS, MASK_MPT | MASK_FMT | MASK_SUS_END); >> + /* rate stability change for inputs A/B */ >> + io_write(sd, REG_INT_MASK_RATE, MASK_RATE_B_ST | MASK_RATE_A_ST); >> + /* aud,spd,avi*/ >> + io_write(sd, REG_INT_MASK_INFO, >> + MASK_AUD_IF | MASK_SPD_IF | MASK_AVI_IF); >> + /* audio_freq,audio_flg,mute_flg,fifo_err */ >> + io_write(sd, REG_INT_MASK_AUDIO, >> + MASK_AUDIO_FREQ_FLG | MASK_AUDIO_FLG | MASK_MUTE_FLG | >> + MASK_ERROR_FIFO_PT); >> + /* HDCP C5 state reached */ >> + io_write(sd, REG_INT_MASK_HDCP, MASK_STATE_C5); >> + /* don't care about AFE/DDC/MODE */ >> + io_write(sd, REG_INT_MASK_AFE, 0); >> + io_write(sd, REG_INT_MASK_DDC, 0); >> + io_write(sd, REG_INT_MASK_MODE, 0); >> + >> + /* clear all interrupts */ >> + io_write(sd, REG_INT_FLG_CLR_TOP, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_SUS, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_DDC, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_RATE, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_MODE, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_INFO, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_AUDIO, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_HDCP, 0xff); >> + io_write(sd, REG_INT_FLG_CLR_AFE, 0xff); >> + >> + /* init TMDS equalizer */ >> + if (state->chip_revision == 0) >> + io_write(sd, REG_CGU_DBG_SEL, 1 << CGU_DBG_CLK_SEL_SHIFT); >> + io_write24(sd, REG_CLK_MIN_RATE, CLK_MIN_RATE); >> + io_write24(sd, REG_CLK_MAX_RATE, CLK_MAX_RATE); >> + if (state->chip_revision == 0) >> + io_write(sd, REG_WDL_CFG, WDL_CFG_VAL); >> + /* DC filter */ >> + io_write(sd, REG_DEEP_COLOR_CTRL, DC_FILTER_VAL); >> + /* disable test pattern */ >> + io_write(sd, REG_SVC_MODE, 0x00); >> + /* update HDMI INFO CTRL */ >> + io_write(sd, REG_INFO_CTRL, 0xff); >> + /* write HDMI INFO EXCEED value */ >> + io_write(sd, REG_INFO_EXCEED, 3); >> + >> + if (state->chip_revision == 0) >> + tda1997x_reset_n1(state); >> + >> + /* >> + * No HDCP acknowledge when HDCP is disabled >> + * and reset SUS to force format detection >> + */ >> + tda1997x_hdmi_info_reset(sd, NACK_HDCP, true); >> + >> + /* Set HPD low */ >> + tda1997x_manual_hpd(sd, HPD_LOW_BP); >> + >> + /* Configure receiver capabilities */ >> + io_write(sd, REG_HDCP_BCAPS, HDCP_HDMI | HDCP_FAST_REAUTH); >> + >> + /* Configure HDMI: Auto HDCP mode, packet controlled mute */ >> + reg = HDMI_CTRL_MUTE_AUTO << HDMI_CTRL_MUTE_SHIFT; >> + reg |= HDMI_CTRL_HDCP_AUTO << HDMI_CTRL_HDCP_SHIFT; >> + io_write(sd, REG_HDMI_CTRL, reg); >> + >> + /* reset start-up-sequencer to force format detection */ >> + tda1997x_hdmi_info_reset(sd, 0, true); >> + >> + /* Set HPD high */ >> + tda1997x_manual_hpd(sd, HPD_HIGH_OTHER); >> + tda1997x_manual_hpd(sd, HPD_HIGH_BP); > > How can you set the HPD high if there is no EDID? No EDID, no HPD. > right - I'll remove this >> + >> + /* disable matrix conversion */ >> + reg = io_read(sd, REG_VDP_CTRL); >> + reg |= VDP_CTRL_MATRIX_BP; >> + io_write(sd, REG_VDP_CTRL, reg); >> + >> + >> + ret = 0x34 + ((io_read(sd, REG_SLAVE_ADDR)>>4) & 0x03); >> + state->client_cec = i2c_new_dummy(client->adapter, ret); >> + v4l_info(client, "CEC slave address 0x%02x\n", ret); >> + >> + ret = tda1997x_core_init(sd); > > Unless I missed it, I don't think state->timings has been initialized > to something valid. During probe the hdmi receiver has to be initialized > to something. The API expects that. Usually VGA or 720p60 or 1080p60 is > chosen for this. you didn't miss it - I didn't know exactly what to do there. I'll initialize it to VGA > >> + if (ret) >> + goto err_free_mutex; >> + >> > > Regards, > > Hans Regarding video standard detection where this chip provides me with vertical-period, horizontal-period, and horizontal-pulse-width I should be able to detect the standard simply based off of vertical-period (framerate) and horizontal-period (line width including blanking) right? I wasn't sure if my method of matching these within 14% tolerance made sense. I will be removing the hsmatch logic from that as it seems the horizontal-pulse-width should be irrelevant. Thanks for the review! Tim