Re: [PATCH] media: uvcvideo: Fix comment blocks style

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Hi Laurent

Out of curiosity, did you just git grep, or did something more clever?

Regards!

On Thu, 9 Jun 2022 at 05:28, Kieran Bingham
<kieran.bingham@xxxxxxxxxxxxxxxx> wrote:
>
> Quoting Laurent Pinchart (2022-06-08 18:43:48)
> > The uvcvideo driver historically uses the
> >
> > /* Comment
> >  * style
> >  */
> >
> > for multi-line block comments, which is frowned upon. Patches for the
> > driver are required to use the more standard
> >
> > /*
> >  * Comment
> >  * style
> >  */
> >
> > style. This result in inconsistencies. Fix it by converting all
> > remaining instances of the old style.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Reviewed-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> > ---
> >  drivers/media/usb/uvc/uvc_ctrl.c   | 33 ++++++----
> >  drivers/media/usb/uvc/uvc_driver.c | 54 +++++++++++------
> >  drivers/media/usb/uvc/uvc_isight.c | 13 ++--
> >  drivers/media/usb/uvc/uvc_queue.c  |  6 +-
> >  drivers/media/usb/uvc/uvc_status.c |  6 +-
> >  drivers/media/usb/uvc/uvc_v4l2.c   | 15 +++--
> >  drivers/media/usb/uvc/uvc_video.c  | 96 ++++++++++++++++++++----------
> >  drivers/media/usb/uvc/uvcvideo.h   | 15 ++---
> >  8 files changed, 156 insertions(+), 82 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> > index 0e78233fc8a0..e1d57602bc37 100644
> > --- a/drivers/media/usb/uvc/uvc_ctrl.c
> > +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> > @@ -749,7 +749,8 @@ static inline void uvc_clear_bit(u8 *data, int bit)
> >         data[bit >> 3] &= ~(1 << (bit & 7));
> >  }
> >
> > -/* Extract the bit string specified by mapping->offset and mapping->size
> > +/*
> > + * Extract the bit string specified by mapping->offset and mapping->size
> >   * from the little-endian data stored at 'data' and return the result as
> >   * a signed 32bit integer. Sign extension will be performed if the mapping
> >   * references a signed data type.
> > @@ -785,7 +786,8 @@ static s32 uvc_get_le_value(struct uvc_control_mapping *mapping,
> >         return value;
> >  }
> >
> > -/* Set the bit string specified by mapping->offset and mapping->size
> > +/*
> > + * Set the bit string specified by mapping->offset and mapping->size
> >   * in the little-endian data stored at 'data' to the value 'value'.
> >   */
> >  static void uvc_set_le_value(struct uvc_control_mapping *mapping,
> > @@ -795,7 +797,8 @@ static void uvc_set_le_value(struct uvc_control_mapping *mapping,
> >         int offset = mapping->offset;
> >         u8 mask;
> >
> > -       /* According to the v4l2 spec, writing any value to a button control
> > +       /*
> > +        * According to the v4l2 spec, writing any value to a button control
> >          * should result in the action belonging to the button control being
> >          * triggered. UVC devices however want to see a 1 written -> override
> >          * value.
> > @@ -927,7 +930,8 @@ static int uvc_ctrl_populate_cache(struct uvc_video_chain *chain,
> >                             UVC_VC_EXTENSION_UNIT)
> >                                 return ret;
> >
> > -                       /* GET_RES is mandatory for XU controls, but some
> > +                       /*
> > +                        * GET_RES is mandatory for XU controls, but some
> >                          * cameras still choke on it. Ignore errors and set the
> >                          * resolution value to zero.
> >                          */
> > @@ -1522,8 +1526,10 @@ static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems)
> >
> >                 uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, val,
> >                                     changes);
> > -               /* Mark the queue as active, allowing this initial
> > -                  event to be accepted. */
> > +               /*
> > +                * Mark the queue as active, allowing this initial event to be
> > +                * accepted.
> > +                */
> >                 sev->elems = elems;
> >                 v4l2_event_queue_fh(sev->fh, &ev);
> >         }
> > @@ -1596,7 +1602,8 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
> >                 if (!ctrl->initialized)
> >                         continue;
> >
> > -               /* Reset the loaded flag for auto-update controls that were
> > +               /*
> > +                * Reset the loaded flag for auto-update controls that were
> >                  * marked as loaded in uvc_ctrl_get/uvc_ctrl_set to prevent
> >                  * uvc_ctrl_get from using the cached value, and for write-only
> >                  * controls to prevent uvc_ctrl_set from setting bits not
> > @@ -1755,7 +1762,8 @@ int uvc_ctrl_set(struct uvc_fh *handle,
> >                         return -ERANGE;
> >                 value = mapping->menu_info[xctrl->value].value;
> >
> > -               /* Valid menu indices are reported by the GET_RES request for
> > +               /*
> > +                * Valid menu indices are reported by the GET_RES request for
> >                  * UVC controls that support it.
> >                  */
> >                 if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK &&
> > @@ -1779,7 +1787,8 @@ int uvc_ctrl_set(struct uvc_fh *handle,
> >                 break;
> >         }
> >
> > -       /* If the mapping doesn't span the whole UVC control, the current value
> > +       /*
> > +        * If the mapping doesn't span the whole UVC control, the current value
> >          * needs to be loaded from the device to perform the read-modify-write
> >          * operation.
> >          */
> > @@ -2180,7 +2189,8 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
> >         unsigned int size;
> >         unsigned int i;
> >
> > -       /* Most mappings come from static kernel data and need to be duplicated.
> > +       /*
> > +        * Most mappings come from static kernel data and need to be duplicated.
> >          * Mappings that come from userspace will be unnecessarily duplicated,
> >          * this could be optimized.
> >          */
> > @@ -2389,7 +2399,8 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
> >         const struct uvc_control_mapping *mend =
> >                 mapping + ARRAY_SIZE(uvc_ctrl_mappings);
> >
> > -       /* XU controls initialization requires querying the device for control
> > +       /*
> > +        * XU controls initialization requires querying the device for control
> >          * information. As some buggy UVC devices will crash when queried
> >          * repeatedly in a tight loop, delay XU controls initialization until
> >          * first use.
> > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> > index 6c86faecbea2..77ac5716f99d 100644
> > --- a/drivers/media/usb/uvc/uvc_driver.c
> > +++ b/drivers/media/usb/uvc/uvc_driver.c
> > @@ -329,7 +329,8 @@ static enum v4l2_ycbcr_encoding uvc_ycbcr_enc(const u8 matrix_coefficients)
> >         return V4L2_YCBCR_ENC_DEFAULT;  /* Reserved */
> >  }
> >
> > -/* Simplify a fraction using a simple continued fraction decomposition. The
> > +/*
> > + * Simplify a fraction using a simple continued fraction decomposition. The
> >   * idea here is to convert fractions such as 333333/10000000 to 1/30 using
> >   * 32 bit arithmetic only. The algorithm is not perfect and relies upon two
> >   * arbitrary parameters to remove non-significative terms from the simple
> > @@ -347,7 +348,8 @@ void uvc_simplify_fraction(u32 *numerator, u32 *denominator,
> >         if (an == NULL)
> >                 return;
> >
> > -       /* Convert the fraction to a simple continued fraction. See
> > +       /*
> > +        * Convert the fraction to a simple continued fraction. See
> >          * https://mathforum.org/dr.math/faq/faq.fractions.html
>
> Not necessarily required for this patch, but this URL doesn't work any
> more.
>
> It redirects to https://www.nctm.org/classroomresources/
>
> But for this patch,
>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
>
> >          * Stop if the current term is bigger than or equal to the given
> >          * threshold.
> > @@ -383,7 +385,8 @@ void uvc_simplify_fraction(u32 *numerator, u32 *denominator,
> >         kfree(an);
> >  }
> >
> > -/* Convert a fraction to a frame interval in 100ns multiples. The idea here is
> > +/*
> > + * Convert a fraction to a frame interval in 100ns multiples. The idea here is
> >   * to compute numerator / denominator * 10000000 using 32 bit fixed point
> >   * arithmetic only.
> >   */
> > @@ -396,7 +399,8 @@ u32 uvc_fraction_to_interval(u32 numerator, u32 denominator)
> >             numerator/denominator >= ((u32)-1)/10000000)
> >                 return (u32)-1;
> >
> > -       /* Divide both the denominator and the multiplier by two until
> > +       /*
> > +        * Divide both the denominator and the multiplier by two until
> >          * numerator * multiplier doesn't overflow. If anyone knows a better
> >          * algorithm please let me know.
> >          */
> > @@ -548,7 +552,8 @@ static int uvc_parse_format(struct uvc_device *dev,
> >
> >                 format->bpp = buffer[21];
> >
> > -               /* Some devices report a format that doesn't match what they
> > +               /*
> > +                * Some devices report a format that doesn't match what they
> >                  * really send.
> >                  */
> >                 if (dev->quirks & UVC_QUIRK_FORCE_Y8) {
> > @@ -663,7 +668,8 @@ static int uvc_parse_format(struct uvc_device *dev,
> >         buflen -= buffer[0];
> >         buffer += buffer[0];
> >
> > -       /* Parse the frame descriptors. Only uncompressed, MJPEG and frame
> > +       /*
> > +        * Parse the frame descriptors. Only uncompressed, MJPEG and frame
> >          * based formats have frame descriptors.
> >          */
> >         while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
> > @@ -705,7 +711,8 @@ static int uvc_parse_format(struct uvc_device *dev,
> >                 }
> >                 frame->dwFrameInterval = *intervals;
> >
> > -               /* Several UVC chipsets screw up dwMaxVideoFrameBufferSize
> > +               /*
> > +                * Several UVC chipsets screw up dwMaxVideoFrameBufferSize
> >                  * completely. Observed behaviours range from setting the
> >                  * value to 1.1x the actual frame size to hardwiring the
> >                  * 16 low bits to 0. This results in a higher than necessary
> > @@ -717,7 +724,8 @@ static int uvc_parse_format(struct uvc_device *dev,
> >                         frame->dwMaxVideoFrameBufferSize = format->bpp
> >                                 * frame->wWidth * frame->wHeight / 8;
> >
> > -               /* Some bogus devices report dwMinFrameInterval equal to
> > +               /*
> > +                * Some bogus devices report dwMinFrameInterval equal to
> >                  * dwMaxFrameInterval and have dwFrameIntervalStep set to
> >                  * zero. Setting all null intervals to 1 fixes the problem and
> >                  * some other divisions by zero that could happen.
> > @@ -727,7 +735,8 @@ static int uvc_parse_format(struct uvc_device *dev,
> >                         *(*intervals)++ = interval ? interval : 1;
> >                 }
> >
> > -               /* Make sure that the default frame interval stays between
> > +               /*
> > +                * Make sure that the default frame interval stays between
> >                  * the boundaries.
> >                  */
> >                 n -= frame->bFrameIntervalType ? 1 : 2;
> > @@ -819,7 +828,8 @@ static int uvc_parse_streaming(struct uvc_device *dev,
> >                 return -ENOMEM;
> >         }
> >
> > -       /* The Pico iMage webcam has its class-specific interface descriptors
> > +       /*
> > +        * The Pico iMage webcam has its class-specific interface descriptors
> >          * after the endpoint descriptors.
> >          */
> >         if (buflen == 0) {
> > @@ -918,7 +928,8 @@ static int uvc_parse_streaming(struct uvc_device *dev,
> >                         break;
> >
> >                 case UVC_VS_FORMAT_DV:
> > -                       /* DV format has no frame descriptor. We will create a
> > +                       /*
> > +                        * DV format has no frame descriptor. We will create a
> >                          * dummy frame descriptor with a dummy frame interval.
> >                          */
> >                         nformats++;
> > @@ -1105,7 +1116,8 @@ static int uvc_parse_vendor_control(struct uvc_device *dev,
> >                 if (buffer[1] != 0x41 || buffer[2] != 0x01)
> >                         break;
> >
> > -               /* Logitech implements several vendor specific functions
> > +               /*
> > +                * Logitech implements several vendor specific functions
> >                  * through vendor specific extension units (LXU).
> >                  *
> >                  * The LXU descriptors are similar to XU descriptors
> > @@ -1303,7 +1315,8 @@ static int uvc_parse_standard_control(struct uvc_device *dev,
> >                         return -EINVAL;
> >                 }
> >
> > -               /* Make sure the terminal type MSB is not null, otherwise it
> > +               /*
> > +                * Make sure the terminal type MSB is not null, otherwise it
> >                  * could be confused with a unit.
> >                  */
> >                 type = get_unaligned_le16(&buffer[4]);
> > @@ -1437,7 +1450,8 @@ static int uvc_parse_control(struct uvc_device *dev)
> >         int buflen = alts->extralen;
> >         int ret;
> >
> > -       /* Parse the default alternate setting only, as the UVC specification
> > +       /*
> > +        * Parse the default alternate setting only, as the UVC specification
> >          * defines a single alternate setting, the default alternate setting
> >          * zero.
> >          */
> > @@ -1455,7 +1469,8 @@ static int uvc_parse_control(struct uvc_device *dev)
> >                 buffer += buffer[0];
> >         }
> >
> > -       /* Check if the optional status endpoint is present. Built-in iSight
> > +       /*
> > +        * Check if the optional status endpoint is present. Built-in iSight
> >          * webcams have an interrupt endpoint but spit proprietary data that
> >          * don't conform to the UVC status endpoint messages. Don't try to
> >          * handle the interrupt endpoint for those cameras.
> > @@ -2057,7 +2072,8 @@ static int uvc_scan_device(struct uvc_device *dev)
> >                 if (!UVC_ENTITY_IS_OTERM(term))
> >                         continue;
> >
> > -               /* If the terminal is already included in a chain, skip it.
> > +               /*
> > +                * If the terminal is already included in a chain, skip it.
> >                  * This can happen for chains that have multiple output
> >                  * terminals, where all output terminals beside the first one
> >                  * will be inserted in the chain in forward scans.
> > @@ -2309,7 +2325,8 @@ static int uvc_register_terms(struct uvc_device *dev,
> >                 if (ret < 0)
> >                         return ret;
> >
> > -               /* Register a metadata node, but ignore a possible failure,
> > +               /*
> > +                * Register a metadata node, but ignore a possible failure,
> >                  * complete registration of video nodes anyway.
> >                  */
> >                 uvc_meta_register(stream);
> > @@ -2507,7 +2524,8 @@ static void uvc_disconnect(struct usb_interface *intf)
> >  {
> >         struct uvc_device *dev = usb_get_intfdata(intf);
> >
> > -       /* Set the USB interface data to NULL. This can be done outside the
> > +       /*
> > +        * Set the USB interface data to NULL. This can be done outside the
> >          * lock, as there's no other reader.
> >          */
> >         usb_set_intfdata(intf, NULL);
> > diff --git a/drivers/media/usb/uvc/uvc_isight.c b/drivers/media/usb/uvc/uvc_isight.c
> > index 2578d6ee4829..43cda5e760a3 100644
> > --- a/drivers/media/usb/uvc/uvc_isight.c
> > +++ b/drivers/media/usb/uvc/uvc_isight.c
> > @@ -14,7 +14,8 @@
> >
> >  #include "uvcvideo.h"
> >
> > -/* Built-in iSight webcams implements most of UVC 1.0 except a
> > +/*
> > + * Built-in iSight webcams implements most of UVC 1.0 except a
> >   * different packet format. Instead of sending a header at the
> >   * beginning of each isochronous transfer payload, the webcam sends a
> >   * single header per image (on its own in a packet), followed by
> > @@ -65,7 +66,8 @@ static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
> >                 buf->state = UVC_BUF_STATE_ACTIVE;
> >         }
> >
> > -       /* Mark the buffer as done if we're at the beginning of a new frame.
> > +       /*
> > +        * Mark the buffer as done if we're at the beginning of a new frame.
> >          *
> >          * Empty buffers (bytesused == 0) don't trigger end of frame detection
> >          * as it doesn't make sense to return an empty buffer.
> > @@ -75,7 +77,8 @@ static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
> >                 return -EAGAIN;
> >         }
> >
> > -       /* Copy the video data to the buffer. Skip header packets, as they
> > +       /*
> > +        * Copy the video data to the buffer. Skip header packets, as they
> >          * contain no data.
> >          */
> >         if (!is_header) {
> > @@ -109,7 +112,9 @@ void uvc_video_decode_isight(struct uvc_urb *uvc_urb, struct uvc_buffer *buf,
> >                                 urb->iso_frame_desc[i].status);
> >                 }
> >
> > -               /* Decode the payload packet.
> > +               /*
> > +                * Decode the payload packet.
> > +                *
> >                  * uvc_video_decode is entered twice when a frame transition
> >                  * has been detected because the end of frame can only be
> >                  * reliably detected when the first packet of the new frame
> > diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> > index 21a907d32bb7..16fa17bbd15e 100644
> > --- a/drivers/media/usb/uvc/uvc_queue.c
> > +++ b/drivers/media/usb/uvc/uvc_queue.c
> > @@ -135,7 +135,8 @@ static void uvc_buffer_queue(struct vb2_buffer *vb)
> >                 kref_init(&buf->ref);
> >                 list_add_tail(&buf->queue, &queue->irqqueue);
> >         } else {
> > -               /* If the device is disconnected return the buffer to userspace
> > +               /*
> > +                * If the device is disconnected return the buffer to userspace
> >                  * directly. The next QBUF call will fail with -ENODEV.
> >                  */
> >                 buf->state = UVC_BUF_STATE_ERROR;
> > @@ -412,7 +413,8 @@ void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
> >
> >         spin_lock_irqsave(&queue->irqlock, flags);
> >         uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
> > -       /* This must be protected by the irqlock spinlock to avoid race
> > +       /*
> > +        * This must be protected by the irqlock spinlock to avoid race
> >          * conditions between uvc_buffer_queue and the disconnection event that
> >          * could result in an interruptible wait in uvc_dequeue_buffer. Do not
> >          * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
> > diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
> > index 753c8226db70..7518ffce22ed 100644
> > --- a/drivers/media/usb/uvc/uvc_status.c
> > +++ b/drivers/media/usb/uvc/uvc_status.c
> > @@ -202,8 +202,7 @@ static void uvc_status_complete(struct urb *urb)
> >         case -ENOENT:           /* usb_kill_urb() called. */
> >         case -ECONNRESET:       /* usb_unlink_urb() called. */
> >         case -ESHUTDOWN:        /* The endpoint is being disabled. */
> > -       case -EPROTO:           /* Device is disconnected (reported by some
> > -                                * host controller). */
> > +       case -EPROTO:           /* Device is disconnected (reported by some host controllers). */
> >                 return;
> >
> >         default:
> > @@ -272,7 +271,8 @@ int uvc_status_init(struct uvc_device *dev)
> >
> >         pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
> >
> > -       /* For high-speed interrupt endpoints, the bInterval value is used as
> > +       /*
> > +        * For high-speed interrupt endpoints, the bInterval value is used as
> >          * an exponent of two. Some developers forgot about it.
> >          */
> >         interval = ep->desc.bInterval;
> > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> > index 648dcd579e81..b36f9cc57cd4 100644
> > --- a/drivers/media/usb/uvc/uvc_v4l2.c
> > +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> > @@ -63,7 +63,8 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
> >                 break;
> >
> >         case V4L2_CTRL_TYPE_MENU:
> > -               /* Prevent excessive memory consumption, as well as integer
> > +               /*
> > +                * Prevent excessive memory consumption, as well as integer
> >                  * overflows.
> >                  */
> >                 if (xmap->menu_count == 0 ||
> > @@ -177,7 +178,8 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> >                 fcc[0], fcc[1], fcc[2], fcc[3],
> >                 fmt->fmt.pix.width, fmt->fmt.pix.height);
> >
> > -       /* Check if the hardware supports the requested format, use the default
> > +       /*
> > +        * Check if the hardware supports the requested format, use the default
> >          * format otherwise.
> >          */
> >         for (i = 0; i < stream->nformats; ++i) {
> > @@ -191,7 +193,8 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> >                 fmt->fmt.pix.pixelformat = format->fcc;
> >         }
> >
> > -       /* Find the closest image size. The distance between image sizes is
> > +       /*
> > +        * Find the closest image size. The distance between image sizes is
> >          * the size in pixels of the non-overlapping regions between the
> >          * requested size and the frame-specified size.
> >          */
> > @@ -233,7 +236,8 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> >         probe->bFormatIndex = format->index;
> >         probe->bFrameIndex = frame->bFrameIndex;
> >         probe->dwFrameInterval = uvc_try_frame_interval(frame, interval);
> > -       /* Some webcams stall the probe control set request when the
> > +       /*
> > +        * Some webcams stall the probe control set request when the
> >          * dwMaxVideoFrameSize field is set to zero. The UVC specification
> >          * clearly states that the field is read-only from the host, so this
> >          * is a webcam bug. Set dwMaxVideoFrameSize to the value reported by
> > @@ -256,7 +260,8 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> >         if (ret < 0)
> >                 goto done;
> >
> > -       /* After the probe, update fmt with the values returned from
> > +       /*
> > +        * After the probe, update fmt with the values returned from
> >          * negotiation with the device. Some devices return invalid bFormatIndex
> >          * and bFrameIndex values, in which case we can only assume they have
> >          * accepted the requested format as-is.
> > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> > index 6d3dfa4e0bb2..170a008f4006 100644
> > --- a/drivers/media/usb/uvc/uvc_video.c
> > +++ b/drivers/media/usb/uvc/uvc_video.c
> > @@ -189,7 +189,8 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
> >                 ctrl->dwMaxVideoFrameSize =
> >                         frame->dwMaxVideoFrameBufferSize;
> >
> > -       /* The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to
> > +       /*
> > +        * The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to
> >          * compute the bandwidth on 16 bits and erroneously sign-extend it to
> >          * 32 bits, resulting in a huge bandwidth value. Detect and fix that
> >          * condition by setting the 16 MSBs to 0 when they're all equal to 1.
> > @@ -207,7 +208,8 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
> >                          ? ctrl->dwFrameInterval
> >                          : frame->dwFrameInterval[0];
> >
> > -               /* Compute a bandwidth estimation by multiplying the frame
> > +               /*
> > +                * Compute a bandwidth estimation by multiplying the frame
> >                  * size by the number of video frames per second, divide the
> >                  * result by the number of USB frames (or micro-frames for
> >                  * high-speed devices) per second and add the UVC header size
> > @@ -220,7 +222,8 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
> >                         bandwidth /= 8;
> >                 bandwidth += 12;
> >
> > -               /* The bandwidth estimate is too low for many cameras. Don't use
> > +               /*
> > +                * The bandwidth estimate is too low for many cameras. Don't use
> >                  * maximum packet sizes lower than 1024 bytes to try and work
> >                  * around the problem. According to measurements done on two
> >                  * different camera models, the value is high enough to get most
> > @@ -267,7 +270,8 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
> >                 size, uvc_timeout_param);
> >
> >         if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
> > -               /* Some cameras, mostly based on Bison Electronics chipsets,
> > +               /*
> > +                * Some cameras, mostly based on Bison Electronics chipsets,
> >                  * answer a GET_MIN or GET_MAX request with the wCompQuality
> >                  * field only.
> >                  */
> > @@ -279,7 +283,8 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
> >                 ret = 0;
> >                 goto out;
> >         } else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
> > -               /* Many cameras don't support the GET_DEF request on their
> > +               /*
> > +                * Many cameras don't support the GET_DEF request on their
> >                  * video probe control. Warn once and return, the caller will
> >                  * fall back to GET_CUR.
> >                  */
> > @@ -322,7 +327,8 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
> >                 ctrl->bMaxVersion = 0;
> >         }
> >
> > -       /* Some broken devices return null or wrong dwMaxVideoFrameSize and
> > +       /*
> > +        * Some broken devices return null or wrong dwMaxVideoFrameSize and
> >          * dwMaxPayloadTransferSize fields. Try to get the value from the
> >          * format and frame descriptors.
> >          */
> > @@ -386,7 +392,8 @@ int uvc_probe_video(struct uvc_streaming *stream,
> >         unsigned int i;
> >         int ret;
> >
> > -       /* Perform probing. The device should adjust the requested values
> > +       /*
> > +        * Perform probing. The device should adjust the requested values
> >          * according to its capabilities. However, some devices, namely the
> >          * first generation UVC Logitech webcams, don't implement the Video
> >          * Probe control properly, and just return the needed bandwidth. For
> > @@ -493,7 +500,8 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
> >         if (len < header_size)
> >                 return;
> >
> > -       /* Extract the timestamps:
> > +       /*
> > +        * Extract the timestamps:
> >          *
> >          * - store the frame PTS in the buffer structure
> >          * - if the SCR field is present, retrieve the host SOF counter and
> > @@ -506,7 +514,8 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
> >         if (!has_scr)
> >                 return;
> >
> > -       /* To limit the amount of data, drop SCRs with an SOF identical to the
> > +       /*
> > +        * To limit the amount of data, drop SCRs with an SOF identical to the
> >          * previous one.
> >          */
> >         dev_sof = get_unaligned_le16(&data[header_size - 2]);
> > @@ -518,7 +527,8 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
> >         host_sof = usb_get_current_frame_number(stream->dev->udev);
> >         time = uvc_video_get_time();
> >
> > -       /* The UVC specification allows device implementations that can't obtain
> > +       /*
> > +        * The UVC specification allows device implementations that can't obtain
> >          * the USB frame number to keep their own frame counters as long as they
> >          * match the size and frequency of the frame number associated with USB
> >          * SOF tokens. The SOF values sent by such devices differ from the USB
> > @@ -756,7 +766,8 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
> >         y1 = NSEC_PER_SEC;
> >         y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1;
> >
> > -       /* Interpolated and host SOF timestamps can wrap around at slightly
> > +       /*
> > +        * Interpolated and host SOF timestamps can wrap around at slightly
> >          * different times. Handle this by adding or removing 2048 to or from
> >          * the computed SOF value to keep it close to the SOF samples mean
> >          * value.
> > @@ -854,7 +865,8 @@ static void uvc_video_stats_decode(struct uvc_streaming *stream,
> >                 stream->stats.frame.pts = pts;
> >         }
> >
> > -       /* Do all frames have a PTS in their first non-empty packet, or before
> > +       /*
> > +        * Do all frames have a PTS in their first non-empty packet, or before
> >          * their first empty packet ?
> >          */
> >         if (stream->stats.frame.size == 0) {
> > @@ -945,7 +957,8 @@ size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,
> >         unsigned int duration;
> >         size_t count = 0;
> >
> > -       /* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF
> > +       /*
> > +        * Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF
> >          * frequency this will not overflow before more than 1h.
> >          */
> >         duration = ktime_ms_delta(stream->stats.stream.stop_ts,
> > @@ -997,7 +1010,8 @@ static void uvc_video_stats_stop(struct uvc_streaming *stream)
> >   * Video codecs
> >   */
> >
> > -/* Video payload decoding is handled by uvc_video_decode_start(),
> > +/*
> > + * Video payload decoding is handled by uvc_video_decode_start(),
> >   * uvc_video_decode_data() and uvc_video_decode_end().
> >   *
> >   * uvc_video_decode_start is called with URB data at the start of a bulk or
> > @@ -1037,7 +1051,8 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> >  {
> >         u8 fid;
> >
> > -       /* Sanity checks:
> > +       /*
> > +        * Sanity checks:
> >          * - packet must be at least 2 bytes long
> >          * - bHeaderLength value must be at least 2 bytes (see above)
> >          * - bHeaderLength value can't be larger than the packet size.
> > @@ -1049,7 +1064,8 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> >
> >         fid = data[1] & UVC_STREAM_FID;
> >
> > -       /* Increase the sequence number regardless of any buffer states, so
> > +       /*
> > +        * Increase the sequence number regardless of any buffer states, so
> >          * that discontinuous sequence numbers always indicate lost frames.
> >          */
> >         if (stream->last_fid != fid) {
> > @@ -1061,7 +1077,8 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> >         uvc_video_clock_decode(stream, buf, data, len);
> >         uvc_video_stats_decode(stream, data, len);
> >
> > -       /* Store the payload FID bit and return immediately when the buffer is
> > +       /*
> > +        * Store the payload FID bit and return immediately when the buffer is
> >          * NULL.
> >          */
> >         if (buf == NULL) {
> > @@ -1076,7 +1093,8 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> >                 buf->error = 1;
> >         }
> >
> > -       /* Synchronize to the input stream by waiting for the FID bit to be
> > +       /*
> > +        * Synchronize to the input stream by waiting for the FID bit to be
> >          * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
> >          * stream->last_fid is initialized to -1, so the first isochronous
> >          * frame will always be in sync.
> > @@ -1102,7 +1120,8 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> >                 buf->state = UVC_BUF_STATE_ACTIVE;
> >         }
> >
> > -       /* Mark the buffer as done if we're at the beginning of a new frame.
> > +       /*
> > +        * Mark the buffer as done if we're at the beginning of a new frame.
> >          * End of frame detection is better implemented by checking the EOF
> >          * bit (FID bit toggling is delayed by one frame compared to the EOF
> >          * bit), but some devices don't set the bit at end of frame (and the
> > @@ -1226,7 +1245,8 @@ static void uvc_video_decode_end(struct uvc_streaming *stream,
> >         }
> >  }
> >
> > -/* Video payload encoding is handled by uvc_video_encode_header() and
> > +/*
> > + * Video payload encoding is handled by uvc_video_encode_header() and
> >   * uvc_video_encode_data(). Only bulk transfers are currently supported.
> >   *
> >   * uvc_video_encode_header is called at the start of a payload. It adds header
> > @@ -1450,7 +1470,8 @@ static void uvc_video_decode_bulk(struct uvc_urb *uvc_urb,
> >         len = urb->actual_length;
> >         stream->bulk.payload_size += len;
> >
> > -       /* If the URB is the first of its payload, decode and save the
> > +       /*
> > +        * If the URB is the first of its payload, decode and save the
> >          * header.
> >          */
> >         if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
> > @@ -1474,7 +1495,8 @@ static void uvc_video_decode_bulk(struct uvc_urb *uvc_urb,
> >                 }
> >         }
> >
> > -       /* The buffer queue might have been cancelled while a bulk transfer
> > +       /*
> > +        * The buffer queue might have been cancelled while a bulk transfer
> >          * was in progress, so we can reach here with buf equal to NULL. Make
> >          * sure buf is never dereferenced if NULL.
> >          */
> > @@ -1483,7 +1505,8 @@ static void uvc_video_decode_bulk(struct uvc_urb *uvc_urb,
> >         if (!stream->bulk.skip_payload && buf != NULL)
> >                 uvc_video_decode_data(uvc_urb, buf, mem, len);
> >
> > -       /* Detect the payload end by a URB smaller than the maximum size (or
> > +       /*
> > +        * Detect the payload end by a URB smaller than the maximum size (or
> >          * a payload size equal to the maximum) and process the header again.
> >          */
> >         if (urb->actual_length < urb->transfer_buffer_length ||
> > @@ -1686,7 +1709,8 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
> >         if (stream->urb_size)
> >                 return stream->urb_size / psize;
> >
> > -       /* Compute the number of packets. Bulk endpoints might transfer UVC
> > +       /*
> > +        * Compute the number of packets. Bulk endpoints might transfer UVC
> >          * payloads across multiple URBs.
> >          */
> >         npackets = DIV_ROUND_UP(size, psize);
> > @@ -1975,7 +1999,8 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream,
> >                 }
> >         }
> >
> > -       /* The Logitech C920 temporarily forgets that it should not be adjusting
> > +       /*
> > +        * The Logitech C920 temporarily forgets that it should not be adjusting
> >          * Exposure Absolute during init so restore controls to stored values.
> >          */
> >         if (stream->dev->quirks & UVC_QUIRK_RESTORE_CTRLS_ON_INIT)
> > @@ -2018,7 +2043,8 @@ int uvc_video_resume(struct uvc_streaming *stream, int reset)
> >  {
> >         int ret;
> >
> > -       /* If the bus has been reset on resume, set the alternate setting to 0.
> > +       /*
> > +        * If the bus has been reset on resume, set the alternate setting to 0.
> >          * This should be the default value, but some devices crash or otherwise
> >          * misbehave if they don't receive a SET_INTERFACE request before any
> >          * other video control request.
> > @@ -2071,14 +2097,16 @@ int uvc_video_init(struct uvc_streaming *stream)
> >
> >         atomic_set(&stream->active, 0);
> >
> > -       /* Alternate setting 0 should be the default, yet the XBox Live Vision
> > +       /*
> > +        * Alternate setting 0 should be the default, yet the XBox Live Vision
> >          * Cam (and possibly other devices) crash or otherwise misbehave if
> >          * they don't receive a SET_INTERFACE request before any other video
> >          * control request.
> >          */
> >         usb_set_interface(stream->dev->udev, stream->intfnum, 0);
> >
> > -       /* Set the streaming probe control with default streaming parameters
> > +       /*
> > +        * Set the streaming probe control with default streaming parameters
> >          * retrieved from the device. Webcams that don't support GET_DEF
> >          * requests on the probe control will just keep their current streaming
> >          * parameters.
> > @@ -2086,7 +2114,8 @@ int uvc_video_init(struct uvc_streaming *stream)
> >         if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)
> >                 uvc_set_video_ctrl(stream, probe, 1);
> >
> > -       /* Initialize the streaming parameters with the probe control current
> > +       /*
> > +        * Initialize the streaming parameters with the probe control current
> >          * value. This makes sure SET_CUR requests on the streaming commit
> >          * control will always use values retrieved from a successful GET_CUR
> >          * request on the probe control, as required by the UVC specification.
> > @@ -2095,7 +2124,8 @@ int uvc_video_init(struct uvc_streaming *stream)
> >         if (ret < 0)
> >                 return ret;
> >
> > -       /* Check if the default format descriptor exists. Use the first
> > +       /*
> > +        * Check if the default format descriptor exists. Use the first
> >          * available format otherwise.
> >          */
> >         for (i = stream->nformats; i > 0; --i) {
> > @@ -2110,7 +2140,8 @@ int uvc_video_init(struct uvc_streaming *stream)
> >                 return -EINVAL;
> >         }
> >
> > -       /* Zero bFrameIndex might be correct. Stream-based formats (including
> > +       /*
> > +        * Zero bFrameIndex might be correct. Stream-based formats (including
> >          * MPEG-2 TS and DV) do not support frames but have a dummy frame
> >          * descriptor with bFrameIndex set to zero. If the default frame
> >          * descriptor is not found, use the first available frame.
> > @@ -2187,7 +2218,8 @@ void uvc_video_stop_streaming(struct uvc_streaming *stream)
> >         if (stream->intf->num_altsetting > 1) {
> >                 usb_set_interface(stream->dev->udev, stream->intfnum, 0);
> >         } else {
> > -               /* UVC doesn't specify how to inform a bulk-based device
> > +               /*
> > +                * UVC doesn't specify how to inform a bulk-based device
> >                  * when the video stream is stopped. Windows sends a
> >                  * CLEAR_FEATURE(HALT) request to the video streaming
> >                  * bulk endpoint, mimic the same behaviour.
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index c5b4febd2d94..d2eb107347ea 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -225,7 +225,8 @@ struct gpio_desc;
> >  struct sg_table;
> >  struct uvc_device;
> >
> > -/* TODO: Put the most frequently accessed fields at the beginning of
> > +/*
> > + * TODO: Put the most frequently accessed fields at the beginning of
> >   * structures to maximize cache efficiency.
> >   */
> >  struct uvc_control_info {
> > @@ -270,8 +271,7 @@ struct uvc_control {
> >         struct uvc_entity *entity;
> >         struct uvc_control_info info;
> >
> > -       u8 index;       /* Used to match the uvc_control entry with a
> > -                          uvc_control_info. */
> > +       u8 index;       /* Used to match the uvc_control entry with a uvc_control_info. */
> >         u8 dirty:1,
> >            loaded:1,
> >            modified:1,
> > @@ -289,7 +289,8 @@ struct uvc_format_desc {
> >         u32 fcc;
> >  };
> >
> > -/* The term 'entity' refers to both UVC units and UVC terminals.
> > +/*
> > + * The term 'entity' refers to both UVC units and UVC terminals.
> >   *
> >   * The type field is either the terminal type (wTerminalType in the terminal
> >   * descriptor), or the unit type (bDescriptorSubtype in the unit descriptor).
> > @@ -308,8 +309,7 @@ struct uvc_format_desc {
> >
> >  struct uvc_entity {
> >         struct list_head list;          /* Entity as part of a UVC device. */
> > -       struct list_head chain;         /* Entity as part of a video device
> > -                                        * chain. */
> > +       struct list_head chain;         /* Entity as part of a video device chain. */
> >         unsigned int flags;
> >
> >         /*
> > @@ -591,7 +591,8 @@ struct uvc_streaming {
> >         struct uvc_format *cur_format;
> >         struct uvc_frame *cur_frame;
> >
> > -       /* Protect access to ctrl, cur_format, cur_frame and hardware video
> > +       /*
> > +        * Protect access to ctrl, cur_format, cur_frame and hardware video
> >          * probe control.
> >          */
> >         struct mutex mutex;
> >
> > base-commit: f2906aa863381afb0015a9eb7fefad885d4e5a56
> > --
> > Regards,
> >
> > Laurent Pinchart
> >



-- 
Ricardo Ribalda



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