Re: [PATCH v2] staging: android: ion: Add implementation of dma_buf_vmap and dma_buf_vunmap

From: Greg KH
Date: Wed Jan 31 2018 - 03:38:37 EST


On Wed, Jan 31, 2018 at 01:44:47AM +0200, alexey wrote:
>
>
> On 01/31/2018 12:15 AM, Greg KH wrote:
> > On Tue, Jan 30, 2018 at 10:39:13PM +0200, Alexey Skidanov wrote:
> > > dma_buf_vmap and dma_buf_vunmap allow drivers to access buffers, created by ion.
> > But why would anyone ever want to do that? What is wrong with the
> > existing interfaces that drivers use to access buffers created by ion?
> Any driver, sharing the buffers, created by ion, through dma-buf, may get
> back the
> sgtable describing the buffer for device DMA  and may call dma_buf_vmap to
> get back
> the kernel virtual address of the buffer to get access to it. Currently, the
> second
> option is missing. Actually, the buffer already mapped by ion
> implementation.

Very odd formatting :(

Anyway, as Dan said, this needs to be put in the changelog text itself.

I know Intel has documentation and training for how to submit patches to
the kernel properly. Please use that resource and get your patch
submission reviewed by someone from the Linux kernel team at Intel
before resending this. Don't force the community to help you learn this
when you have people whose job it is to help out with this at your
company :)

thanks,

greg k-h