Hi, On Sun, Dec 7, 2014 at 9:23 PM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Grazvydas, > > (CC'ing Paulo Assis) > > On Saturday 06 December 2014 02:25:25 Grazvydas Ignotas wrote: >> On Fri, Dec 5, 2014 at 1:46 PM, Laurent Pinchart wrote: >> > On Thursday 06 November 2014 00:29:53 Grazvydas Ignotas wrote: >> >> On Wed, Nov 5, 2014 at 4:05 PM, Laurent Pinchart wrote: >> >> > Would you be able to capture images from the C920 using yavta, with the >> >> > uvcvideo trace parameter set to 4096, and send me both the yavta log >> >> > and the kernel log ? Let's start with a capture sequence of 50 to 100 >> >> > images. >> >> >> >> I've done 2 captures, if that helps: >> >> http://notaz.gp2x.de/tmp/c920_yavta/ >> >> >> >> The second one was done using low exposure setting, which allows >> >> camera to achieve higher frame rate. >> > >> > Thank you for the log, they were very helpful. They revealed that the USB >> > SOF (Start Of Frame) counter values on the device and host side are not >> > in sync. The counters get incremented are very different rates. What USB >> > controller are you using ? >> >> 00:1d.7 USB controller: Intel Corporation NM10/ICH7 Family USB2 EHCI >> Controller (rev 01) (prog-if 20 [EHCI]) >> Subsystem: Micro-Star International Co., Ltd. [MSI] Device 7592 >> Flags: bus master, medium devsel, latency 0, IRQ 23 >> Memory at fe9fbc00 (32-bit, non-prefetchable) [size=1K] >> Capabilities: [50] Power Management version 2 >> Capabilities: [58] Debug port: BAR=1 offset=00a0 >> Kernel driver in use: ehci-pci >> >> If it helps, I could try on an ARM board, currently don't have any >> other x86 hardware around. > > Actually the frequencies I've computed from the log are correct on the host > side but quite off on the device side. I'm puzzled. > > The following patch allows accessing the contents of the clock data buffer > through debugfs. Would you be able to apply it and execute the following > steps ? > > 1. Load the uvcvideo module with the clock trace flag (0x1000) set. > > 2. Start capturing clock data. > > while true; do > cat /sys/kernel/debug/usb/uvcvideo/2-6/clocks ; > done > ~/samples.log > > 3. Capture 100 frames. > > yavta -c100 > yavta.log > > 4. Stop the "while true" with ctrl-C. > > 5. Capture the uvcvideo stats. > > cat /sys/kernel/debug/usb/uvcvideo/2-6/stats > stats.log > > 6. Capture the kernel log. > > dmesg > dmesg.log > > 7. Send me all the log files. Done: http://notaz.gp2x.de/tmp/c920_yavta/3/ -- Gražvydas -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
