On Tue, Jul 04, 2017 at 03:54:46PM -0400, Trevor Childs wrote: > I meant -- what hardware generates that signal? > > The Linux system is an Nvidia Jetson TX1 developer kit, running Ubuntu > 16.04. The output is done over the board's HDMI (2.1, type A) port, either > direct into the recorder or through an AJA HA5-4K HDMI to SDI converter.
Well, documentation said that the most default pixel clock source for HDMI is PLL_D2, and it have precision clock stepping: either 38.4 MHz / DIVM * DIVN / DIVP (SDM disabled) or 38.4 MHz / DIVM * (DIVN + 0.5 + SDM_DIN/8192) / DIVP (SDM enabled) DIVM, DIVN 8-bit, SDM_DIN 16 bit. I miss the point whether it is further divided by 2 Anyway, something like SDM, M=1, N=14, SDM_DIN=7936 (or M=1, N=28, SDM_DIN=19968) should get exactly 940 MHz pixel clock. So, rounding to picoseconds looks like error in NVidia kernel code, please fix it yourself or ask them to fix it. _______________________________________________ xorg@lists.x.org: X.Org support Archives: http://lists.freedesktop.org/archives/xorg Info: https://lists.x.org/mailman/listinfo/xorg Your subscription address: %(user_address)s
