Re: [PATCH] spi-topcliff-pch: Fix probing when DMA mode is used

[Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>]

On Friday 28 February 2014 12:43:31, Mark Brown wrote:
> On Thu, Feb 27, 2014 at 09:13:21AM +0100, Alexander Stein wrote:
> > On Thursday 27 February 2014 13:37:19, Mark Brown wrote:
> > > On Wed, Feb 26, 2014 at 04:31:19PM +0100, Alexander Stein wrote:
> > > > If during registering SPI master due to SPI device probing a SPI transfer
> > > > is issued the DMA buffers are not allocated yet.
> 
> > > Applied, thanks.
> 
> > Thinking about this patch over night, this also should go to stable, no?
> 
> Possibly, though I'd have thought that someone would have noticed by now
> if there were any affected systems using stable?

Well, i think this is a rather rarely use case. You need either all drivers compiled in where the SPI device driver is loaded before SPI master or you need SPI master als module while the SPI device driver is already compiled in. Oh, and the SPI device driver must do a SPI transfer during probe. So the conditions are reptty strict when this problem might happen.

Alexander

PS: On EG20T (PCH) it seems this will never happen as the DMA channels are allocated wrongly (see other patch from me) andso DMA will never be used.

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