RE: dma engine drivers for 2.6.25?

[Zhang Wei]

Hi,

Sorry for missing lots of emails in my long vacation. :)

> -----Original Message-----
> From: dan.j.williams@xxxxxxxxx 
> [mailto:dan.j.williams@xxxxxxxxx] On Behalf Of Dan Williams
> Sent: Sunday, February 24, 2008 10:06 AM
> To: Kumar Gala
> Cc: LKML Kernel; Zhang Wei
> Subject: Re: dma engine drivers for 2.6.25?
> 
> On Thu, Feb 14, 2008 at 10:29 PM, Dan Williams 
> <dan.j.williams@xxxxxxxxx> wrote:
> > On Thu, Feb 14, 2008 at 8:44 PM, Kumar Gala 
> <galak@xxxxxxxxxxxxxxxxxxx> wrote:
> >  >
> >  >  On Feb 14, 2008, at 12:14 PM, Dan Williams wrote:
> >  >
> >  >  > On Wed, Feb 13, 2008 at 8:52 PM, Kumar Gala
> >  >  > <galak@xxxxxxxxxxxxxxxxxxx> wrote:
> >  >  >> Dan,
> >  >  >>
> >  >  >> What's going on with the dma engine drivers for 
> 2.6.25?  We had a
> >  >  >> Freescale dma driver from Zhang Wei queued up but 
> seems to have been
> >  >  >> lost.
> >  >  >
> >  >  > I pulled it into my tree and am holding it until Zhang has an
> >  >  > opportunity to address the pending review comments 
> [1].  I also did
> >  >  > not feel comfortable pushing it to Linus without a 
> PPC maintainer's
> >  >  > Acked-by/Reviewed-by.
> >  >  >
> >  >  > I have attached the version I am carrying.
> >  >
> >  >  What issues are still open.  I was under the belief 
> that Zhang had
> >  >  resolved all the issues.
> >  >
> >
> >  The high priority review item is that the driver performs operation
> >  completion callbacks in hardirq context.  Clients of the API assume
> >  that callbacks will happen in softirq context.  Of lesser 
> concern is
> >  the use of GFP_ATOMIC in fsl_dma_alloc_descriptor.  Other drivers
> >  preallocate a small pool of descriptors.
> >
> 
> Have not received a response, so let's try this the other way.  I took
> a closer look and found that my concern should be addressed by the
> following one-liner:
> 
> diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
> index 902e852..cc9a681 100644
> --- a/drivers/dma/fsldma.c
> +++ b/drivers/dma/fsldma.c
> @@ -685,7 +685,6 @@ static irqreturn_t fsl_dma_chan_do_interrupt(int
> irq, void *data)
>                                 "nlndar 0x%016llx\n", 
> (u64)get_cdar(fsl_chan),
>                                 (u64)get_ndar(fsl_chan));
>                 stat &= ~FSL_DMA_SR_EOSI;
> -               fsl_chan_ld_cleanup(fsl_chan);
>         }
> 
>         /* If it current transfer is the end-of-transfer,
> 
> With your ack I'll push the driver plus this fixlet for the 
> current kernel.

I agree with you to remove the fsl_chan_ld_cleanup() function calling in
Interrupt action, which is already called in tasklet. I forgot to remove it.
Thanks!

Cheers!
Wei.

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