Re: [PATCH v3 23/23] media: atmel: atmel-isc: change format propagation to subdev into only verification

Eugen.Hristev
2022-01-20T08:43:55Z

On 1/12/22 11:21 AM, Jacopo Mondi wrote:
> Hi Eugen

Hi Jacopo,

>
> On Mon, Dec 13, 2021 at 03:49:40PM +0200, Eugen Hristev wrote:
>> As a top MC video driver, the atmel-isc should not propagate the format to the
>> subdevice.
>> It should rather check at streamon() time if the subdev is properly configured
>> with a compatible format.
>> Removed the whole format finding logic, and reworked the format verification
>> at streamon time, such that the ISC will return an error if the subdevice
>> is not properly configured.
>> With this being done, the module parameter 'sensor_prefered' makes no sense
>> anymore. The ISC should not decide which format the sensor is using. The
>> ISC should only cope with the situation and inform userspace if the streaming
>> is possible in the current configuration.
>
> Sounds great!
>
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>> ---
>> Changes in v3:
>> - clamp to maximum resolution once the frame size from the subdev is found
>>
>> drivers/media/platform/atmel/atmel-isc-base.c | 271 ++++++++----------
>> drivers/media/platform/atmel/atmel-isc.h | 1 +
>> 2 files changed, 126 insertions(+), 146 deletions(-)
>>
>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>> index 31c8e3029eee..00c8c9588a78 100644
>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>> @@ -36,11 +36,6 @@ static unsigned int debug;
>> module_param(debug, int, 0644);
>> MODULE_PARM_DESC(debug, "debug level (0-2)");
>>
>> -static unsigned int sensor_preferred = 1;
>> -module_param(sensor_preferred, uint, 0644);
>> -MODULE_PARM_DESC(sensor_preferred,
>> - "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>> -
>> #define ISC_IS_FORMAT_RAW(mbus_code) \
>> (((mbus_code) & 0xf000) == 0x3000)
>>
>> @@ -532,7 +527,7 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
>> * convert it to any of the formats that we usually can with a
>> * RAW sensor. Thus, do not advertise them.
>> */
>> - if (!isc->config.sd_format ||
>> + if (isc->config.sd_format &&
>
> Is this change intentional ?
>
>> !ISC_IS_FORMAT_RAW(isc->config.sd_format->mbus_code))
>> return -EINVAL;
>>
>> @@ -621,20 +616,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
>> break;
>> default:
>> /* any other different formats are not supported */
>> + v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
>> ret = -EINVAL;
>> }
>> v4l2_dbg(1, debug, &isc->v4l2_dev,
>> "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
>> rgb, yuv, grey, bayer);
>
> Would it make sense to move this before the switch so that the
> error messages, if any, appear later ?

Actually, no, because the variables rgb, yuv, grey, bayer, are set
according to what happens in the switch
>
>>
>> - /* we cannot output RAW if we do not receive RAW */
>> - if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>> + if ((bayer) &&
>> + !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
>> + v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
>> return -EINVAL;
>> + }
>>
>> - /* we cannot output GREY if we do not receive RAW/GREY */
>> if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
>> - !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
>> + !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>> + v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
>> return -EINVAL;
>> + }
>> +
>> + if ((rgb || bayer || yuv) &&
>> + ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>> + v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
>> + return -EINVAL;
>> + }
>>
>> return ret;
>> }
>> @@ -862,7 +867,7 @@ static void isc_try_fse(struct isc_device *isc,
>> * If we do not know yet which format the subdev is using, we cannot
>> * do anything.
>> */
>> - if (!isc->try_config.sd_format)
>> + if (!isc->config.sd_format)
>> return;
>>
>> fse.code = isc->try_config.sd_format->mbus_code;
>> @@ -883,180 +888,141 @@ static void isc_try_fse(struct isc_device *isc,
>> }
>> }
>>
>> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
>> - u32 *code)
>> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
>> {
>> - int i;
>> - struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
>> struct v4l2_pix_format *pixfmt = &f->fmt.pix;
>> - struct v4l2_subdev_pad_config pad_cfg = {};
>> - struct v4l2_subdev_state pad_state = {
>> - .pads = &pad_cfg
>> - };
>> - struct v4l2_subdev_format format = {
>> - .which = V4L2_SUBDEV_FORMAT_TRY,
>> - };
>> - u32 mbus_code;
>> - int ret;
>> - bool rlp_dma_direct_dump = false;
>> + unsigned int i;
>>
>> if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>> return -EINVAL;
>>
>> - /* Step 1: find a RAW format that is supported */
>> - for (i = 0; i < isc->num_user_formats; i++) {
>> - if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
>> - sd_fmt = isc->user_formats[i];
>> + isc->try_config.fourcc = isc->user_formats[0]->fourcc;
>> +
>> + /* find if the format requested is supported */
>> + for (i = 0; i < isc->controller_formats_size; i++)
>> + if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
>> + isc->try_config.fourcc = pixfmt->pixelformat;
>> break;
>> }
>> - }
>> - /* Step 2: We can continue with this RAW format, or we can look
>> - * for better: maybe sensor supports directly what we need.
>> - */
>> - direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
>> -
>> - /* Step 3: We have both. We decide given the module parameter which
>> - * one to use.
>> - */
>> - if (direct_fmt && sd_fmt && sensor_preferred)
>> - sd_fmt = direct_fmt;
>> -
>> - /* Step 4: we do not have RAW but we have a direct format. Use it. */
>> - if (direct_fmt && !sd_fmt)
>> - sd_fmt = direct_fmt;
>> -
>> - /* Step 5: if we are using a direct format, we need to package
>> - * everything as 8 bit data and just dump it
>> - */
>> - if (sd_fmt == direct_fmt)
>> - rlp_dma_direct_dump = true;
>> -
>> - /* Step 6: We have no format. This can happen if the userspace
>> - * requests some weird/invalid format.
>> - * In this case, default to whatever we have
>> - */
>> - if (!sd_fmt && !direct_fmt) {
>> - sd_fmt = isc->user_formats[isc->num_user_formats - 1];
>> - v4l2_dbg(1, debug, &isc->v4l2_dev,
>> - "Sensor not supporting %.4s, using %.4s\n",
>> - (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
>> - }
>> -
>> - if (!sd_fmt) {
>> - ret = -EINVAL;
>> - goto isc_try_fmt_err;
>> - }
>> -
>> - /* Step 7: Print out what we decided for debugging */
>> - v4l2_dbg(1, debug, &isc->v4l2_dev,
>> - "Preferring to have sensor using format %.4s\n",
>> - (char *)&sd_fmt->fourcc);
>> -
>> - /* Step 8: at this moment we decided which format the subdev will use */
>> - isc->try_config.sd_format = sd_fmt;
>> -
>> - /* Limit to Atmel ISC hardware capabilities */
>> - if (pixfmt->width > isc->max_width)
>> - pixfmt->width = isc->max_width;
>> - if (pixfmt->height > isc->max_height)
>> - pixfmt->height = isc->max_height;
>> -
>> - /*
>> - * The mbus format is the one the subdev outputs.
>> - * The pixels will be transferred in this format Sensor -> ISC
>> - */
>> - mbus_code = sd_fmt->mbus_code;
>> -
>> - /*
>> - * Validate formats. If the required format is not OK, default to raw.
>> - */
>> -
>> - isc->try_config.fourcc = pixfmt->pixelformat;
>> -
>> - if (isc_try_validate_formats(isc)) {
>> - pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
>> - /* Re-try to validate the new format */
>> - ret = isc_try_validate_formats(isc);
>> - if (ret)
>> - goto isc_try_fmt_err;
>> - }
>> -
>> - ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
>> - if (ret)
>> - goto isc_try_fmt_err;
>> -
>> - ret = isc_try_configure_pipeline(isc);
>> - if (ret)
>> - goto isc_try_fmt_err;
>>
>> - /* Obtain frame sizes if possible to have crop requirements ready */
>> - isc_try_fse(isc, &pad_state);
>> -
>> - v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
>> - ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
>> - &pad_state, &format);
>> - if (ret < 0)
>> - goto isc_try_fmt_subdev_err;
>> + /* If we did not find the requested format, we will fallback here */
>> + pixfmt->pixelformat = isc->try_config.fourcc;
>> + pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
>> + pixfmt->field = V4L2_FIELD_NONE;
>>
>> - v4l2_fill_pix_format(pixfmt, &format.format);
>> + isc_try_configure_rlp_dma(isc, false);
>>
>> /* Limit to Atmel ISC hardware capabilities */
>> - if (pixfmt->width > isc->max_width)
>> - pixfmt->width = isc->max_width;
>> - if (pixfmt->height > isc->max_height)
>> - pixfmt->height = isc->max_height;
>> + v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
>> + &pixfmt->height, 16, isc->max_height, 0, 0);
>>
>> pixfmt->field = V4L2_FIELD_NONE;
>> pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
>> pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
>> pixfmt->height;
>>
>> - if (code)
>> - *code = mbus_code;
>> + isc->try_fmt = *f;
>>
>> return 0;
>> +}
>>
>> -isc_try_fmt_err:
>> - v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
>> -isc_try_fmt_subdev_err:
>> - memset(&isc->try_config, 0, sizeof(isc->try_config));
>> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>> +{
>> + isc_try_fmt(isc, f);
>>
>> - return ret;
>> + /* make the try configuration active */
>> + isc->config = isc->try_config;
>> + isc->fmt = isc->try_fmt;
>> +
>> + v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
>> + (char *)&f->fmt.pix.pixelformat,
>> + f->fmt.pix.width, f->fmt.pix.height);
>> +
>> + return 0;
>> }
>>
>> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>> +static int isc_validate(struct isc_device *isc)
>> {
>> + int ret;
>> + int i;
>> + struct isc_format *sd_fmt = NULL;
>> + struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
>> struct v4l2_subdev_format format = {
>> .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>> + .pad = isc->remote_pad,
>> + };
>> + struct v4l2_subdev_pad_config pad_cfg = {};
>> + struct v4l2_subdev_state pad_state = {
>> + .pads = &pad_cfg,
>> };
>> - u32 mbus_code = 0;
>> - int ret;
>>
>> - ret = isc_try_fmt(isc, f, &mbus_code);
>> + /* Get current format from subdev */
>> + ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
>> + &format);
>
> Ah! Haven't you just said we don't care anymore about the subdev
> format ? :)

We don't ! but we can't stream anything if the sensor streams a format
that we don't understand do we ?

>
> Kidding, I might got a bit lost in the logic, but if I look at your
> above isc_try_validate_formats() it seems like an ideal candidate for
> .link_validate() media_entity operation.
>
> Just to make sure we're on the same page, here's how it should ideally
> look like:
> - set format does care about subdev format. It only checks that the
> format required from the user is one of the ISC supported one. Ie.
> no v4l2_subdev_call()
>
> - as s_stream time your top driver calls media_pipeline_start()
>
> - media_pipeline_start() walks all the entities in the pipeline and
> validates the format of connected pads. To validate formats the
> __media_pipeline_start() functions calls link_validate() on each
> entity. You should in your driver set

Is this done automatically ? if this would be the case, where all links
are correctly set, then, in theory, it would not be possible that some
entities have a format set that is not supported by the other side

>
> static const struct media_entity_operations your_media_entity_ops = {
> .link_validate = v4l2_subdev_link_validate,
> };
>
> if you want to use the default link validation procedure, or set the
> callback to your custom validation function, which can behave more
> or less like isc_try_validate_formats()

Does this mean that I can ask the subdev for the format ?
Or how can I obtain the format on the other side of the link ?
link validate can do this for me ?

Thanks for reviewing,
Eugen
>
> Does it match your understanding too ?
>
> Thanks
> j
>
>
>
>> if (ret)
>> return ret;
>>
>> - v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
>> - ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
>> - set_fmt, NULL, &format);
>> - if (ret < 0)
>> - return ret;
>> + /* Identify the subdev's format configuration */
>> + for (i = 0; i < isc->num_user_formats; i++)
>> + if (isc->user_formats[i]->mbus_code == format.format.code) {
>> + sd_fmt = isc->user_formats[i];
>> + break;
>> + }
>> +
>> + /* Check if the format is not supported */
>> + if (!sd_fmt) {
>> + v4l2_err(&isc->v4l2_dev,
>> + "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
>> + format.format.code);
>> + return -EPIPE;
>> + }
>> +
>> + /* At this moment we know which format the subdev will use */
>> + isc->try_config.sd_format = sd_fmt;
>> +
>> + /* If the sensor is not RAW, we can only do a direct dump */
>> + if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>> + isc_try_configure_rlp_dma(isc, true);
>>
>> /* Limit to Atmel ISC hardware capabilities */
>> - if (f->fmt.pix.width > isc->max_width)
>> - f->fmt.pix.width = isc->max_width;
>> - if (f->fmt.pix.height > isc->max_height)
>> - f->fmt.pix.height = isc->max_height;
>> + v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
>> + &format.format.height, 16, isc->max_height, 0, 0);
>>
>> - isc->fmt = *f;
>> + /* Check if the frame size is the same. Otherwise we may overflow */
>> + if (pixfmt->height != format.format.height ||
>> + pixfmt->width != format.format.width) {
>> + v4l2_err(&isc->v4l2_dev,
>> + "ISC not configured with the proper frame size: %dx%d\n",
>> + format.format.width, format.format.height);
>> + return -EPIPE;
>> + }
>>
>> + v4l2_dbg(1, debug, &isc->v4l2_dev,
>> + "Identified subdev using format %.4s with %dx%d %d bpp\n",
>> + (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
>> + isc->try_config.bpp);
>> +
>> + /* Reset and restart AWB if the subdevice changed the format */
>> if (isc->try_config.sd_format && isc->config.sd_format &&
>> isc->try_config.sd_format != isc->config.sd_format) {
>> isc->ctrls.hist_stat = HIST_INIT;
>> isc_reset_awb_ctrls(isc);
>> isc_update_v4l2_ctrls(isc);
>> }
>> - /* make the try configuration active */
>> +
>> + /* Validate formats */
>> + ret = isc_try_validate_formats(isc);
>> + if (ret)
>> + return ret;
>> +
>> + /* Obtain frame sizes if possible to have crop requirements ready */
>> + isc_try_fse(isc, &pad_state);
>> +
>> + /* Configure ISC pipeline for the config */
>> + ret = isc_try_configure_pipeline(isc);
>> + if (ret)
>> + return ret;
>> +
>> isc->config = isc->try_config;
>>
>> v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
>> @@ -1064,6 +1030,19 @@ static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>> return 0;
>> }
>>
>> +static int isc_streamon(struct file *file, void *priv, enum v4l2_buf_type bt)
>> +{
>> + struct isc_device *isc = video_drvdata(file);
>> + int ret;
>> +
>> + ret = isc_validate(isc);
>> +
>> + if (ret)
>> + return ret;
>> +
>> + return vb2_ioctl_streamon(file, priv, bt);
>> +}
>> +
>> static int isc_s_fmt_vid_cap(struct file *file, void *priv,
>> struct v4l2_format *f)
>> {
>> @@ -1080,7 +1059,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
>> {
>> struct isc_device *isc = video_drvdata(file);
>>
>> - return isc_try_fmt(isc, f, NULL);
>> + return isc_try_fmt(isc, f);
>> }
>>
>> static int isc_enum_input(struct file *file, void *priv,
>> @@ -1176,7 +1155,7 @@ static const struct v4l2_ioctl_ops isc_ioctl_ops = {
>> .vidioc_dqbuf = vb2_ioctl_dqbuf,
>> .vidioc_create_bufs = vb2_ioctl_create_bufs,
>> .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
>> - .vidioc_streamon = vb2_ioctl_streamon,
>> + .vidioc_streamon = isc_streamon,
>> .vidioc_streamoff = vb2_ioctl_streamoff,
>>
>> .vidioc_g_parm = isc_g_parm,
>> @@ -1879,7 +1858,7 @@ static int isc_set_default_fmt(struct isc_device *isc)
>> };
>> int ret;
>>
>> - ret = isc_try_fmt(isc, &f, NULL);
>> + ret = isc_try_fmt(isc, &f);
>> if (ret)
>> return ret;
>>
>> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
>> index c2cb805faff3..7081698adddd 100644
>> --- a/drivers/media/platform/atmel/atmel-isc.h
>> +++ b/drivers/media/platform/atmel/atmel-isc.h
>> @@ -297,6 +297,7 @@ struct isc_device {
>> struct completion comp;
>>
>> struct v4l2_format fmt;
>> + struct v4l2_format try_fmt;
>> struct isc_format **user_formats;
>> unsigned int num_user_formats;
>>
>> --
>> 2.25.1
>>