lkml.org 
[lkml]   [2011]   [Feb]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: b44 driver causes panic when using swiotlb
From
On Mon, 31 Jan 2011 21:22:23 -0600
Robert Hancock <hancockrwd@gmail.com> wrote:

> > Some ideas to implement something that works for such device were
> > discussed. Seems that the conclusion is that it's doesn't worth making
> > the common code complicated for such minor and insane devices.
>
> I don't think this is the only device that has sub-32-bit DMA
> restrictions, this will just lead to a bunch of duplicated code.

Yeah, not only device but not many.

The block layer has the own bouncing mechanism. Some network drivers
have the similar bouncing code. I don't know if there are other kinds
of drivers that have the own bouncing code.

I thought that we can make mm/bounce.c (used for block drivers now)
work any drivers without complicating it. We could make swiotlb to do
but it's too complicated and it doesn't worth.


> In
> particular, how is LPC DMA supposed to work?

LPC DMA can't do 32bit dma?


> At the very least we should be allowing the driver to deal with the
> failure instead of panicing the system. Otherwise we are just leaving a
> land mine for people to trip over.

Agreed. swiotlb shouldn't panic in this case. I'll take care of it.


\
 
 \ /
  Last update: 2011-02-01 06:25    [W:0.062 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site