lkml.org 
[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
From
Date
On Wed, 2018-08-08 at 22:57 +0200, Wolfram Sang wrote:
> On Sat, Jul 07, 2018 at 05:29:54PM +0800, Jun Gao wrote:
> > From: Jun Gao <jun.gao@mediatek.com>
> >
> > This function is needed by i2c_get_dma_safe_msg_buf() potentially.
> > It is used to free DMA safe buffer when DMA operation fails.
> >
> > Signed-off-by: Jun Gao <jun.gao@mediatek.com>
>
> Right, we need something like this. This leaks in the sh_mobile driver,
> too :(
>
> I am still thinking if there is a nice way to put this functionality
> into i2c_release_dma_safe_msg_buf() itself somehow...

Wolfram,

I have second thought on these API now. Recently, we have saw similar
issue for spi device driver.

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
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?

Joe.C


\
 
 \ /
  Last update: 2018-08-09 11:14    [W:0.066 / U:4.840 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site