On 28-04-20, 14:35, Andy Shevchenko wrote: > If we do > > % echo 1 > /sys/module/dmatest/parameters/run > [ 115.851124] dmatest: Could not start test, no channels configured > > % echo dma8chan7 > /sys/module/dmatest/parameters/channel > [ 127.563872] dmatest: Added 1 threads using dma8chan7 > > % cat /sys/module/dmatest/parameters/wait > ... !!! HANG !!! ... > > The culprit is the commit 6138f967bccc > > ("dmaengine: dmatest: Use fixed point div to calculate iops") > > which makes threads not to run, but pending and being kicked off by writing > to the 'run' node. However, it forgot to consider 'wait' routine to avoid > above mentioned case. > > In order to fix this, check for really running threads, i.e. with pending > and done flags unset. > > It's pity the culprit commit hadn't updated documentation and tested all > possible scenarios. Applied, thanks -- ~Vinod