Hi Songjun,
It was an advice from Hans, I copy/paste the comment here:
http://www.mail-archive.com/linux-media@vger.kernel.org/msg112338.html
>> + /* Enable stream on the sub device */
>> + ret = v4l2_subdev_call(dcmi->entity.subdev, video, s_stream, 1);
>> + if (ret && ret != -ENOIOCTLCMD) {
>> + dev_err(dcmi->dev, "%s: Failed to start streaming, subdev
>> streamon error",
>> + __func__);
>> + goto err_release_buffers;
>> + }
>> +
>> + if (clk_enable(dcmi->mclk)) {
>> + dev_err(dcmi->dev, "%s: Failed to start streaming, cannot
>> enable clock",
>> + __func__);
>> + goto err_subdev_streamoff;
>> + }
>It feels more natural to me to first enable the clock, then call
>s_stream.
Please note that I have not tested code, but only reported changes done
in ST DCMI driver to reflect the same on ISI driver, would it be
possible that you check that it is still functional on your side ?
Best regards,
Hugues.
On 05/22/2017 07:02 AM, Wu, Songjun wrote:
> Hi Hugues,
>
> Thank you for your patch.
> Is it necessary to ensure ISI is clocked before starting sensor sub device?
>
> On 5/19/2017 20:08, Hugues FRUCHET wrote:
>> Adding Songjun and Ludovic as Atmel maintainers, sorry for inconvenience.
>>
>> On 05/19/2017 12:04 PM, Hugues Fruchet wrote:
>>> Ensure that ISI is clocked before starting sensor sub device.
>>> Remove un-needed type check in try_fmt().
>>> Use clamp() macro for hardware capabilities.
>>> Fix wrong tabulation to space.
>>>
>>> Signed-off-by: Hugues Fruchet <hugues.fruc...@st.com>
>>> ---
>>> drivers/media/platform/atmel/atmel-isi.c | 24
>>> ++++++++++--------------
>>> 1 file changed, 10 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/atmel/atmel-isi.c
>>> b/drivers/media/platform/atmel/atmel-isi.c
>>> index e4867f8..7bf9f7d 100644
>>> --- a/drivers/media/platform/atmel/atmel-isi.c
>>> +++ b/drivers/media/platform/atmel/atmel-isi.c
>>> @@ -36,8 +36,8 @@
>>> #include "atmel-isi.h"
>>> -#define MAX_SUPPORT_WIDTH 2048
>>> -#define MAX_SUPPORT_HEIGHT 2048
>>> +#define MAX_SUPPORT_WIDTH 2048U
>>> +#define MAX_SUPPORT_HEIGHT 2048U
>>> #define MIN_FRAME_RATE 15
>>> #define FRAME_INTERVAL_MILLI_SEC (1000 / MIN_FRAME_RATE)
>>> @@ -424,6 +424,8 @@ static int start_streaming(struct vb2_queue *vq,
>>> unsigned int count)
>>> struct frame_buffer *buf, *node;
>>> int ret;
>>> + pm_runtime_get_sync(isi->dev);
>>> +
>>> /* Enable stream on the sub device */
>>> ret = v4l2_subdev_call(isi->entity.subdev, video, s_stream, 1);
>>> if (ret && ret != -ENOIOCTLCMD) {
>>> @@ -431,8 +433,6 @@ static int start_streaming(struct vb2_queue *vq,
>>> unsigned int count)
>>> goto err_start_stream;
>>> }
>>> - pm_runtime_get_sync(isi->dev);
>>> -
>>> /* Reset ISI */
>>> ret = atmel_isi_wait_status(isi, WAIT_ISI_RESET);
>>> if (ret < 0) {
>>> @@ -455,10 +455,11 @@ static int start_streaming(struct vb2_queue
>>> *vq, unsigned int count)
>>> return 0;
>>> err_reset:
>>> - pm_runtime_put(isi->dev);
>>> v4l2_subdev_call(isi->entity.subdev, video, s_stream, 0);
>>> err_start_stream:
>>> + pm_runtime_put(isi->dev);
>>> +
>>> spin_lock_irq(&isi->irqlock);
>>> isi->active = NULL;
>>> /* Release all active buffers */
>>> @@ -566,20 +567,15 @@ static int isi_try_fmt(struct atmel_isi *isi,
>>> struct v4l2_format *f,
>>> };
>>> int ret;
>>> - if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>>> - return -EINVAL;
>>> -
>>> isi_fmt = find_format_by_fourcc(isi, pixfmt->pixelformat);
>>> if (!isi_fmt) {
>>> isi_fmt = isi->user_formats[isi->num_user_formats - 1];
>>> pixfmt->pixelformat = isi_fmt->fourcc;
>>> }
>>> - /* Limit to Atmel ISC hardware capabilities */
>>> - if (pixfmt->width > MAX_SUPPORT_WIDTH)
>>> - pixfmt->width = MAX_SUPPORT_WIDTH;
>>> - if (pixfmt->height > MAX_SUPPORT_HEIGHT)
>>> - pixfmt->height = MAX_SUPPORT_HEIGHT;
>>> + /* Limit to Atmel ISI hardware capabilities */
>>> + pixfmt->width = clamp(pixfmt->width, 0U, MAX_SUPPORT_WIDTH);
>>> + pixfmt->height = clamp(pixfmt->height, 0U, MAX_SUPPORT_HEIGHT);
>>> v4l2_fill_mbus_format(&format.format, pixfmt,
>>> isi_fmt->mbus_code);
>>> ret = v4l2_subdev_call(isi->entity.subdev, pad, set_fmt,
>>> @@ -1058,7 +1054,7 @@ static int isi_graph_notify_complete(struct
>>> v4l2_async_notifier *notifier)
>>> struct atmel_isi *isi = notifier_to_isi(notifier);
>>> int ret;
>>> - isi->vdev->ctrl_handler = isi->entity.subdev->ctrl_handler;
>>> + isi->vdev->ctrl_handler = isi->entity.subdev->ctrl_handler;
>>> ret = isi_formats_init(isi);
>>> if (ret) {
>>> dev_err(isi->dev, "No supported mediabus format found\n");
