Messages in this thread | | | From | Appana Durga Kedareswara Rao <> | Subject | RE: [PATCH v5 3/3] dmaengine: xilinx_dma: Fix race condition in the driver for multiple descriptor scenario | Date | Fri, 13 Jan 2017 06:33:33 +0000 |
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Hi Vinod,
Thanks for the review...
[Snip] > > > Btw how and when does DMA stop, assuming it is circular it never > > > would, isn't there a valid/stop flag associated with a descriptor > > > which tells DMA engine what to do next > > > > There are two registers that controls the DMA transfers. > > Current descriptor and tail descriptor register. > > When current descriptor reaches tail descriptor dma engine will pause. > > > > When reprogramming the tail descriptor the DMA engine will starts fetching > descriptors again. > > > > But with the existing driver flow if we reprogram the tail descriptor > > The tail descriptor next descriptor field is pointing to an invalid > > location Causing data corruption... > > So the solution is..?
This patch. I mean if we have a set of descriptors in chain (in circular manner last descriptor points to first descriptor) It always points to valid descriptors.
Will update the patch commit description in the next version...
> > > > Btw there is something wrong with your MUA perhaps line are > > > titlecased for no reason. This is typically behavious of non linux > > > tool which may not be great tool for this work. > > > > Thanks for pointing it out. > > I usually replies from outlook from a windows machine. > > Will check with others in my team how they configured their mail client. > > Yeah that isnt right tool for the job. See Documentation/process/email- > clients.rst > > FWIW, I use mutt, vim as editor with exchange servers, seems to work well for > me now.
Thanks for pointing it out will go through it. Will install mutt in my Linux machine will start replying from that
Regards, Kedar.
> > -- > ~Vinod
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