The userspace comedilib function 'get_cmd_generic_timed' fills the cmd structure with an informed guess and then calls the function 'usbduxfast_ai_cmdtest' in this driver repeatedly while 'usbduxfast_ai_cmdtest' is modifying the cmd struct until it no longer changes. However, because of rounding errors this never converged because 'steps = (cmd->convert_arg * 30) / 1000' and then back to 'cmd->convert_arg = (steps * 1000) / 30' won't be the same because of rounding errors. 'Steps' should only be converted back to the 'convert_arg' if 'steps' has actually been modified. In addition the case of steps being 0 wasn't checked which is also now done. Signed-off-by: Bernd Porr <mail@berndporr.me.uk> Cc: <stable@vger.kernel.org> # 4.4+ Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20191118230759.1727-1-mail@berndporr.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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|---|---|---|
| .. | ||
| drivers | ||
| kcomedilib | ||
| comedi_buf.c | ||
| comedi_compat32.c | ||
| comedi_compat32.h | ||
| comedi_fops.c | ||
| comedi_internal.h | ||
| comedi_pci.c | ||
| comedi_pci.h | ||
| comedi_pcmcia.c | ||
| comedi_pcmcia.h | ||
| comedi_usb.c | ||
| comedi_usb.h | ||
| comedi.h | ||
| comedidev.h | ||
| comedilib.h | ||
| drivers.c | ||
| Kconfig | ||
| Makefile | ||
| proc.c | ||
| range.c | ||
| TODO | ||