Add some fixes for fixing hw timestamp on some Logitech and SunplusIT
cameras. The issues have been previously reported to the manufacturers.
Also include a patch to fix the current hw timestamping logic for ANY
uvc 1.5 model running at under 16 fps.
To: Laurent Pinchart <[email protected]>
To: Mauro Carvalho Chehab <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: hn.chen <[email protected]>
Tested-by: HungNien Chen <[email protected]>
Signed-off-by: Ricardo Ribalda <[email protected]>
---
Changes in v4 (Thanks Laurent!):
- Rebase on top of pinchart/next/uvc
- Use heuristic for UVC_QUIRK_IGNORE_EMPTY_TS
- Link to v3: https://lore.kernel.org/r/[email protected]
Changes in v3 (Thanks Laurent!):
- Rebase on top of pinchart/uvc/next
- Fix hw timestampt handling for slow FPS
- Improve commit message
- Quirk for invalid dev_sof in Logi C922
- Improve commit message
- Allow hw clock updates with buffers not full
- Fix typo and improve messages
- Refactor clock circular buffer
- Improve commit message
- Quirk for autosuspend in Logi C910
- Improve commit message
- Add comments around the quirk
- Create UVC_QUIRK_IGNORE_EMPTY_TS quirk
- Improve comments
- Allow quirking by entity guid
- unsinged int
- Extend documentation of uvc_video_clock_decode()
- uvcvideo on commit message
- Improve comment
- Link to v2: https://lore.kernel.org/r/[email protected]
Changes in v2:
- Require 1/4 sec of data before using the hw timestamps
- Add Tested-by SunplusIT
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Ricardo Ribalda (5):
media: uvc: Ignore empty TS packets
media: uvcvideo: Quirk for invalid dev_sof in Logitech C922
media: uvcvideo: Allow hw clock updates with buffers not full
media: uvcvideo: Refactor clock circular buffer
media: uvcvideo: Fix hw timestamp handling for slow FPS
drivers/media/usb/uvc/uvc_driver.c | 9 +++
drivers/media/usb/uvc/uvc_video.c | 123 ++++++++++++++++++++++++-------------
drivers/media/usb/uvc/uvcvideo.h | 2 +
3 files changed, 91 insertions(+), 43 deletions(-)
---
base-commit: 73d6709376914f577a61bb29e596fa93ec66598c
change-id: 20220920-resend-hwtimestamp-b3e22729284d
Best regards,
--
Ricardo Ribalda <[email protected]>
Logitech C922 internal SOF does not increases at a stable rate of 1kHz.
This causes that the device_sof and the host_sof run at different rates,
breaking the clock domain conversion algorithm. Eg:
30 (6) [-] none 30 614400 B 21.245557 21.395214 34.133 fps ts mono/SoE
31 (7) [-] none 31 614400 B 21.275327 21.427246 33.591 fps ts mono/SoE
32 (0) [-] none 32 614400 B 21.304739 21.459256 34.000 fps ts mono/SoE
33 (1) [-] none 33 614400 B 21.334324 21.495274 33.801 fps ts mono/SoE
* 34 (2) [-] none 34 614400 B 21.529237 21.527297 5.130 fps ts mono/SoE
* 35 (3) [-] none 35 614400 B 21.649416 21.559306 8.321 fps ts mono/SoE
36 (4) [-] none 36 614400 B 21.678789 21.595320 34.045 fps ts mono/SoE
...
99 (3) [-] none 99 614400 B 23.542226 23.696352 33.541 fps ts mono/SoE
100 (4) [-] none 100 614400 B 23.571578 23.728404 34.069 fps ts mono/SoE
101 (5) [-] none 101 614400 B 23.601425 23.760420 33.504 fps ts mono/SoE
* 102 (6) [-] none 102 614400 B 23.798324 23.796428 5.079 fps ts mono/SoE
* 103 (7) [-] none 103 614400 B 23.916271 23.828450 8.478 fps ts mono/SoE
104 (0) [-] none 104 614400 B 23.945720 23.860479 33.957 fps ts mono/SoE
Instead of disabling completely the hardware timestamping for such
hardware we take the assumption that the packet handling jitter is
under 2ms and use the host_sof as dev_sof.
We can think of the UVC hardware clock as a system with a coarse clock
(the SOF) and a fine clock (the PTS). The coarse clock can be replaced
with a clock on the same frequency, if the jitter of such clock is
smaller than its sampling rate. That way we can save some of the
precision of the fine clock.
To probe this point we have run three experiments on the Logitech C922.
On that experiment we run the camera at 33fps and we analyse the
difference in msec between a frame and its predecessor. If we display
the histogram of that value, a thinner histogram will mean a better
meassurement. The results for:
- original hw timestamp: https://ibb.co/D1HJJ4x
- pure software timestamp: https://ibb.co/QC9MgVK
- modified hw timestamp: https://ibb.co/8s9dBdk
This bug in the camera firmware has been confirmed by the vendor.
lsusb -v
Bus 001 Device 044: ID 046d:085c Logitech, Inc. C922 Pro Stream Webcam
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x046d Logitech, Inc.
idProduct 0x085c C922 Pro Stream Webcam
bcdDevice 0.16
iManufacturer 0
iProduct 2 C922 Pro Stream Webcam
iSerial 1 80B912DF
bNumConfigurations 1
Signed-off-by: Ricardo Ribalda <[email protected]>
---
drivers/media/usb/uvc/uvc_driver.c | 9 +++++++++
drivers/media/usb/uvc/uvc_video.c | 8 +++++++-
drivers/media/usb/uvc/uvcvideo.h | 1 +
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index c1e3c1fab976..eae88d0f420e 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2569,6 +2569,15 @@ static const struct usb_device_id uvc_ids[] = {
.bInterfaceSubClass = 1,
.bInterfaceProtocol = 0,
.driver_info = UVC_INFO_QUIRK(UVC_QUIRK_RESTORE_CTRLS_ON_INIT) },
+ /* Logitech HD Pro Webcam C922 */
+ { .match_flags = USB_DEVICE_ID_MATCH_DEVICE
+ | USB_DEVICE_ID_MATCH_INT_INFO,
+ .idVendor = 0x046d,
+ .idProduct = 0x085c,
+ .bInterfaceClass = USB_CLASS_VIDEO,
+ .bInterfaceSubClass = 1,
+ .bInterfaceProtocol = 0,
+ .driver_info = UVC_INFO_QUIRK(UVC_QUIRK_INVALID_DEVICE_SOF) },
/* Chicony CNF7129 (Asus EEE 100HE) */
{ .match_flags = USB_DEVICE_ID_MATCH_DEVICE
| USB_DEVICE_ID_MATCH_INT_INFO,
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 710165502b5b..ecd3c1292182 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -541,7 +541,13 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
stream->clock.last_sof = dev_sof;
- host_sof = usb_get_current_frame_number(stream->dev->udev);
+ /*
+ * On some devices, like the Logitech C922, the device SOF does not run
+ * at a stable rate of 1kHz. For those devices use the host SOF instead.
+ */
+ if (stream->dev->quirks & UVC_QUIRK_INVALID_DEVICE_SOF)
+ dev_sof = usb_get_current_frame_number(stream->dev->udev);
+
time = uvc_video_get_time();
/*
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 22656755a801..699c33bc24ed 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -73,6 +73,7 @@
#define UVC_QUIRK_FORCE_Y8 0x00000800
#define UVC_QUIRK_FORCE_BPP 0x00001000
#define UVC_QUIRK_WAKE_AUTOSUSPEND 0x00002000
+#define UVC_QUIRK_INVALID_DEVICE_SOF 0x00004000
/* Format flags */
#define UVC_FMT_FLAG_COMPRESSED 0x00000001
--
2.39.0.314.g84b9a713c41-goog-b4-0.11.0-dev-696ae