Re: [PATCH 0/3] dmaengine: Stear users towards dma_request_slave_chan()

From: Vinod Koul
Date: Wed Feb 05 2020 - 06:59:13 EST


On 05-02-20, 13:56, Peter Ujfalusi wrote:
> Hi Vinod,
>
> On 05/02/2020 13.31, Vinod Koul wrote:
> >> Looking at the commit which added it and I still don't get the point.
> >> If any of the channel is in use then we should not allow the DMA driver
> >> to go away at all.
> >
> > Not really, if the device is already gone, we cant do much about it. We
> > have to handle that gracefully rather than oopsing
>
> Ah, I have not thought about that. True.
>
> > The important part is that the device is gone. Think about a device on
> > PCI card which is yanked off or a USB device unplugged. Device is
> > already gone, you can't communicate with it anymore. So all we can do is
> > handle the condition and exit, hence the new method to let driver know.
>
> But for most devices this is not applicable, I also wondered what should
> I do in order to silence the print. Just add an empty device_release?

I will send a patch removing this before we hit release :) so nothing to
be done unless you have a hotpluggable device then would be good to add this.

Thanks
--
~Vinod