Coding Support

Steve Markgraf steve at
Thu Aug 15 20:08:30 UTC 2019

Hi Robert,

On 15.08.19 17:50, Hudspeth, Robert Lee wrote:
> I'm trying to run utilities that capture 978
> <> & 1090Mhz
> <> traffic simultaneously, but I
> can't seem to stop rtl_sdr from allocating too many zero-copy buffers
> and preventing both programs from running simultaneously (I'd like to
> cut down from 15). I've been through librtlsdr.c and rtl_adsb.c with the
> hope of manually changing some variable that will let me accomplish this
> to no avail. 

Just increase the usbfs memory limit, the default is only 16MB.
Either write the new size, or completely disable the limit with:

echo 0 > /sys/module/usbcore/parameters/usbfs_memory_mb


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