Hi,
I'm running TI's Linux 2.6.37 as provided in ti-sdk-am37x-evm-05.05.01.00 PSP. I've managed to exercise the processor's HW scaling capabilities using V4L, resizing from YUV16 640x512 to 720x576, as documented here:
http://processors.wiki.ti.com/index.php/UserGuideDisplayDrivers_PSP_04.02.00.07#Scaling
Problems arise when trying to downscale a V4L video stream from YUV16 1024x768 to 720x576 (kernel dmesg error follows):
omapdss DISPC error: failed to set up scaling, required fclk rate = 109881533 Hz, current fclk rate = 96000000 Hz
I've reconfigured U-Boot to set a higer frequency for DISPC FCLK (arch/arm/cpu/armv7/omap3/lowlevel_init.S), but as it grows the message persists, always demanding a higher FCLK rate.
Also, I've studied the kernel source code producing this error (drivers/video/omap2/dss/dispc.c), and it seems really "hacky" to me: hardcoded values of image properties, lots of FIXMEs, etc. Also, newer versions of this file in more recent kernels seem to change heavily, even redesign, this part of the kernel entirely.
Please help,
Emilio.