> > +static unsigned long global_flags;
> Is the restriction on concurrent DMA RX streams global or per-device?

? Each device has only one DMA RX channel. Hey Simon, you upstreamed
this driver :) Or did I get the question wrong?

> > +   if (dir == DMA_FROM_DEVICE)
> > +           clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
> > +
> Is clear_bit() expensive? If so it might be worth avoiding on SoCs that
> don't have the restriction covered by this patch.

It's an atoimc bitop, so maybe has a memory barrier. Hmm, the above
version is better on the cache lines, though, if you don't have the

Will think about it and make sure both clear_bit() are in sync.

Attachment: signature.asc
Description: PGP signature

Reply via email to