Hi,
On 9/12/22 13:30, Andy Shevchenko wrote:
> On Sun, Sep 11, 2022 at 07:16:41PM +0200, Hans de Goede wrote:
>> Several of the ioctl handlers all do the same checks
>> (isp->fatal_error and asd->streaming errors) add
>> an atomisp_pipe_check() helper for this.
>>
>> Note this changes the vidioc_s_fmt_vid_cap and vidioc_s_input handlers
>> to now reject calls made while asd->streaming==STOPPING. This fixes
>> a possible race where one thread can make this ioctls while
>> vidioc_streamoff is running from another thread and it has
>> temporarily released isp->mutex to kill the watchdog timers / work.
>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
> (One minor question below)
>
>> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>> ---
>> .../staging/media/atomisp/pci/atomisp_cmd.c | 9 +-
>> .../staging/media/atomisp/pci/atomisp_ioctl.c | 89 +++++++++----------
>> .../staging/media/atomisp/pci/atomisp_ioctl.h | 2 +
>> 3 files changed, 48 insertions(+), 52 deletions(-)
>>
>> diff --git a/drivers/staging/media/atomisp/pci/atomisp_cmd.c b/drivers/staging/media/atomisp/pci/atomisp_cmd.c
>> index 087078900415..7945852ecd13 100644
>> --- a/drivers/staging/media/atomisp/pci/atomisp_cmd.c
>> +++ b/drivers/staging/media/atomisp/pci/atomisp_cmd.c
>> @@ -5549,16 +5549,13 @@ int atomisp_set_fmt(struct video_device *vdev, struct v4l2_format *f)
>> struct v4l2_subdev_fh fh;
>> int ret;
>>
>> - lockdep_assert_held(&isp->mutex);
>> + ret = atomisp_pipe_check(pipe, true);
>> + if (ret)
>> + return ret;
>>
>> if (source_pad >= ATOMISP_SUBDEV_PADS_NUM)
>> return -EINVAL;
>>
>> - if (asd->streaming == ATOMISP_DEVICE_STREAMING_ENABLED) {
>> - dev_warn(isp->dev, "ISP does not support set format while at streaming!\n");
>> - return -EBUSY;
>> - }
>> -
>> dev_dbg(isp->dev,
>> "setting resolution %ux%u on pad %u for asd%d, bytesperline %u\n",
>> f->fmt.pix.width, f->fmt.pix.height, source_pad,
>> diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
>> index 9c7022be3a06..9b50f637c46a 100644
>> --- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
>> +++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
>> @@ -535,6 +535,32 @@ atomisp_get_format_bridge_from_mbus(u32 mbus_code)
>> return NULL;
>> }
>>
>> +int atomisp_pipe_check(struct atomisp_video_pipe *pipe, bool settings_change)
>> +{
>> + lockdep_assert_held(&pipe->isp->mutex);
>> +
>> + if (pipe->isp->isp_fatal_error)
>> + return -EIO;
>> +
>> + switch (pipe->asd->streaming) {
>> + case ATOMISP_DEVICE_STREAMING_DISABLED:
>> + break;
>> + case ATOMISP_DEVICE_STREAMING_ENABLED:
>> + if (settings_change) {
>> + dev_err(pipe->isp->dev, "Set fmt/input IOCTL while streaming\n");
>> + return -EBUSY;
>> + }
>> + break;
>
>> + case ATOMISP_DEVICE_STREAMING_STOPPING:
>> + dev_err(pipe->isp->dev, "IOCTL issued while stopping\n");
>> + return -EBUSY;
>
> Wouldn't -EAGAIN match better in this case?
The original checks this replaces used -EIO (which seems like a poor
choice) resp. -EBUSY (in the streamon callback) so I decided to
keep the -EBUSY here.
Also AFAIK -EAGAIN will make the C-library retry the syscal itself
in some cases ? (not sure if this applies to ioctls though).
This is not what we want, this scenario can only be hit when an app:
1. Uses both the preview and the actual capture /dev/video# nodes
at the same time (this is allows)
2. Then stops the stream at 1 of them, this transitions the state
to STOPPING
3. Then does some ioctl other then streamoff on the other /dev/video#
Basically when using more then 1 /dev/video# node then the app must
stop all of them when stopping things. The driver enforces this
by rejecting all calls other the streamoff until all /dev/video#
node streans are off.
This means that simply trying again will result in the same error,
so -EBUSY seems like the best error for this.
Regards,
Hans
>
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> /*
>> * v4l2 ioctls
>> * return ISP capabilities
>> @@ -646,12 +672,18 @@ static int atomisp_s_input(struct file *file, void *fh, unsigned int input)
>> {
>> struct video_device *vdev = video_devdata(file);
>> struct atomisp_device *isp = video_get_drvdata(vdev);
>> - struct atomisp_sub_device *asd = atomisp_to_video_pipe(vdev)->asd;
>> + struct atomisp_video_pipe *pipe = atomisp_to_video_pipe(vdev);
>> + struct atomisp_sub_device *asd = pipe->asd;
>> struct v4l2_subdev *camera = NULL;
>> struct v4l2_subdev *motor;
>> int ret;
>>
>> mutex_lock(&isp->mutex);
>> +
>> + ret = atomisp_pipe_check(pipe, true);
>> + if (ret)
>> + goto error;
>> +
>> if (input >= ATOM_ISP_MAX_INPUTS || input >= isp->input_cnt) {
>> dev_dbg(isp->dev, "input_cnt: %d\n", isp->input_cnt);
>> ret = -EINVAL;
>> @@ -678,13 +710,6 @@ static int atomisp_s_input(struct file *file, void *fh, unsigned int input)
>> goto error;
>> }
>>
>> - if (atomisp_subdev_streaming_count(asd)) {
>> - dev_err(isp->dev,
>> - "ISP is still streaming, stop first\n");
>> - ret = -EINVAL;
>> - goto error;
>> - }
>> -
>> /* power off the current owned sensor, as it is not used this time */
>> if (isp->inputs[asd->input_curr].asd == asd &&
>> asd->input_curr != input) {
>> @@ -976,11 +1001,6 @@ static int atomisp_s_fmt_cap(struct file *file, void *fh,
>> int ret;
>>
>> mutex_lock(&isp->mutex);
>> - if (isp->isp_fatal_error) {
>> - ret = -EIO;
>> - mutex_unlock(&isp->mutex);
>> - return ret;
>> - }
>> ret = atomisp_set_fmt(vdev, f);
>> mutex_unlock(&isp->mutex);
>> return ret;
>> @@ -1236,20 +1256,13 @@ static int atomisp_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
>> struct ia_css_frame *handle = NULL;
>> u32 length;
>> u32 pgnr;
>> - int ret = 0;
>> + int ret;
>>
>> mutex_lock(&isp->mutex);
>> - if (isp->isp_fatal_error) {
>> - ret = -EIO;
>> - goto error;
>> - }
>>
>> - if (asd->streaming == ATOMISP_DEVICE_STREAMING_STOPPING) {
>> - dev_err(isp->dev, "%s: reject, as ISP at stopping.\n",
>> - __func__);
>> - ret = -EIO;
>> + ret = atomisp_pipe_check(pipe, false);
>> + if (ret)
>> goto error;
>> - }
>>
>> if (!buf || buf->index >= VIDEO_MAX_FRAME ||
>> !pipe->capq.bufs[buf->index]) {
>> @@ -1418,23 +1431,13 @@ static int atomisp_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
>> struct atomisp_video_pipe *pipe = atomisp_to_video_pipe(vdev);
>> struct atomisp_sub_device *asd = pipe->asd;
>> struct atomisp_device *isp = video_get_drvdata(vdev);
>> - int ret = 0;
>> + int ret;
>>
>> mutex_lock(&isp->mutex);
>> -
>> - if (isp->isp_fatal_error) {
>> - mutex_unlock(&isp->mutex);
>> - return -EIO;
>> - }
>> -
>> - if (asd->streaming == ATOMISP_DEVICE_STREAMING_STOPPING) {
>> - mutex_unlock(&isp->mutex);
>> - dev_err(isp->dev, "%s: reject, as ISP at stopping.\n",
>> - __func__);
>> - return -EIO;
>> - }
>> -
>> + ret = atomisp_pipe_check(pipe, false);
>> mutex_unlock(&isp->mutex);
>> + if (ret)
>> + return ret;
>>
>> ret = videobuf_dqbuf(&pipe->capq, buf, file->f_flags & O_NONBLOCK);
>> if (ret) {
>> @@ -1668,8 +1671,8 @@ static int atomisp_streamon(struct file *file, void *fh,
>> enum ia_css_pipe_id css_pipe_id;
>> unsigned int sensor_start_stream;
>> unsigned int wdt_duration = ATOMISP_ISP_TIMEOUT_DURATION;
>> - int ret = 0;
>> unsigned long irqflags;
>> + int ret;
>>
>> dev_dbg(isp->dev, "Start stream on pad %d for asd%d\n",
>> atomisp_subdev_source_pad(vdev), asd->index);
>> @@ -1680,15 +1683,9 @@ static int atomisp_streamon(struct file *file, void *fh,
>> }
>>
>> mutex_lock(&isp->mutex);
>> - if (isp->isp_fatal_error) {
>> - ret = -EIO;
>> - goto out;
>> - }
>> -
>> - if (asd->streaming == ATOMISP_DEVICE_STREAMING_STOPPING) {
>> - ret = -EBUSY;
>> + ret = atomisp_pipe_check(pipe, false);
>> + if (ret)
>> goto out;
>> - }
>>
>> if (pipe->capq.streaming)
>> goto out;
>> diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.h b/drivers/staging/media/atomisp/pci/atomisp_ioctl.h
>> index 382b78275240..61a6148a6ad5 100644
>> --- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.h
>> +++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.h
>> @@ -34,6 +34,8 @@ atomisp_format_bridge *atomisp_get_format_bridge(unsigned int pixelformat);
>> const struct
>> atomisp_format_bridge *atomisp_get_format_bridge_from_mbus(u32 mbus_code);
>>
>> +int atomisp_pipe_check(struct atomisp_video_pipe *pipe, bool streaming_ok);
>> +
>> int atomisp_alloc_css_stat_bufs(struct atomisp_sub_device *asd,
>> uint16_t stream_id);
>>
>> --
>> 2.37.3
>>
>
