[PATCH v2 08/13] dmaengine: at_xdmac: Move the free desc to the tail of the desc list

Tudor.Ambarus at microchip.com Tudor.Ambarus at microchip.com
Mon Dec 13 00:51:25 PST 2021


Hi, Vinod,

On 12/13/21 10:07 AM, Vinod Koul wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On 25-11-21, 11:00, Tudor Ambarus wrote:
>> So that we don't use the same desc over and over again.
> 
> Please use full para in the changelog and not a continuation of the
> patch title!

Ok, will add a better commit description. Here and in other patches where
your comment applies.

> 
> and why is wrong with using same desc over and over? Any benefits of not
> doing so?

Not wrong, but if we move the free desc to the tail of the list, then the
sequence of descriptors is more track-able in case of debug. You would
know which descriptor should come next and you could easier catch
concurrency over descriptors for example. I saw virt-dma uses
list_splice_tail_init() as well, I found it a good idea, so I thought to
follow the core driver.

Cheers,
ta


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