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Re: [PATCHv6 3/8] dma-mapping: add dma_{map,unmap}_resource

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  Re: [PATCHv6 3/8] dma-mapping: add dma_{map,unmap}_resource Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-05-17 17:00 +0200
    Re: [PATCHv6 3/8] dma-mapping: add dma_{map,unmap}_resource "Niklas Söderlund" <niklas.soderlund@ragnatech.se> - 2016-05-19 13:30 +0200
      Re: [PATCHv6 3/8] dma-mapping: add dma_{map,unmap}_resource Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-05-19 16:30 +0200

#1402402 — Re: [PATCHv6 3/8] dma-mapping: add dma_{map,unmap}_resource

>  
> -In some circumstances dma_map_single() and dma_map_page() will fail to create
> -a mapping. A driver can check for these errors by testing the returned
> -DMA address with dma_mapping_error(). A non-zero return value means the mapping
> -could not be created and the driver should take appropriate action (e.g.
> -reduce current DMA mapping usage or delay and try again later).
> +In some circumstances dma_map_single(), dma_map_page() and dma_map_resource()
> +will fail to create a mapping. A driver can check for these errors by testing
> +the returned DMA address with dma_mapping_error(). A non-zero return value
> +means the mapping could not be created and the driver should take appropriate
> +action (e.g. reduce current DMA mapping usage or delay and try again later).

This looks like it belongs to another patch?

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#1403658

Hi Konrad,

Thanks for your feedback.

On 2016-05-17 10:54:45 -0400, Konrad Rzeszutek Wilk wrote:
> >  
> > -In some circumstances dma_map_single() and dma_map_page() will fail to create
> > -a mapping. A driver can check for these errors by testing the returned
> > -DMA address with dma_mapping_error(). A non-zero return value means the mapping
> > -could not be created and the driver should take appropriate action (e.g.
> > -reduce current DMA mapping usage or delay and try again later).
> > +In some circumstances dma_map_single(), dma_map_page() and dma_map_resource()
> > +will fail to create a mapping. A driver can check for these errors by testing
> > +the returned DMA address with dma_mapping_error(). A non-zero return value
> > +means the mapping could not be created and the driver should take appropriate
> > +action (e.g. reduce current DMA mapping usage or delay and try again later).
> 
> This looks like it belongs to another patch?

No it is correct (at least intended to be in this patch). All it really 
do is inject dma_map_resource() (which is added in this patch) as one of 
the calls which return dma_addr_t should be checked for error using 
dma_mapping_error().  But yes the change effect all lines in the 
paragraph due to line wrapping.

Hum or maybe I'm misunderstanding your question.

-- 
Regards,
Niklas Söderlund

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#1403779

On Thu, May 19, 2016 at 01:29:26PM +0200, Niklas Söderlund wrote:
> Hi Konrad,
> 
> Thanks for your feedback.
> 
> On 2016-05-17 10:54:45 -0400, Konrad Rzeszutek Wilk wrote:
> > >  
> > > -In some circumstances dma_map_single() and dma_map_page() will fail to create
> > > -a mapping. A driver can check for these errors by testing the returned
> > > -DMA address with dma_mapping_error(). A non-zero return value means the mapping
> > > -could not be created and the driver should take appropriate action (e.g.
> > > -reduce current DMA mapping usage or delay and try again later).
> > > +In some circumstances dma_map_single(), dma_map_page() and dma_map_resource()
> > > +will fail to create a mapping. A driver can check for these errors by testing
> > > +the returned DMA address with dma_mapping_error(). A non-zero return value
> > > +means the mapping could not be created and the driver should take appropriate
> > > +action (e.g. reduce current DMA mapping usage or delay and try again later).
> > 
> > This looks like it belongs to another patch?
> 
> No it is correct (at least intended to be in this patch). All it really 
> do is inject dma_map_resource() (which is added in this patch) as one of 
> the calls which return dma_addr_t should be checked for error using 
> dma_mapping_error().  But yes the change effect all lines in the 
> paragraph due to line wrapping.
> 
> Hum or maybe I'm misunderstanding your question.

I totally missed the 'dma_map_resource' in there and just read
'dma_mapping_error'!

<sigh> Thanks.
> 
> -- 
> Regards,
> Niklas Söderlund

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