[lkml]   [2018]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v2 2/3] i2c: Add helper to ease DMA handling

> I believe the reason for these api is because some arch changed to can
> not do DMA on stack recently. Maybe we should have dma_mapping to bounce

It is not only arch dependent. You can enable virtual stacks in Kconfig,

> buffer like it bounce un-dma-able address for those arch? or we should
> have a common driver API for this, not just for i2c?

I gave a talk about this problem recently and everyone in the room
agreed the best thing would be to have annotated buffers which can be
used kernel-wide. Someone mentioned DMABUF could be a candidate, but I
haven't looked further into that.

So, yes, a bigger solution is needed but I don't see that coming soon,
so I implemented the I2C part for better safety now. I'd be happy to
remove all that again once we have the annotated buffers. But it is an



[unhandled content-type:application/pgp-signature]
 \ /
  Last update: 2018-08-09 11:24    [W:0.032 / U:8.484 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site