Re: [PATCH] drivers: mmc: msm: update to new arm pfn_to_dma API

[Daniel Walker <dwalker@codeaurora.org>]

On Tue, 2011-01-18 at 21:16 +0000, Russell King - ARM Linux wrote:
> On Tue, Jan 18, 2011 at 01:00:20PM -0800, Daniel Walker wrote:
> > Just greping the driver I found at least one writel() .. I'm not really
> > concerned with that tho. I use this driver, I need this driver to work.
> > You broke the driver, and your NAK'ing the fix ..
> 
> If drivers use documented internal APIs, they _will_ break, and that's
> tough luck.  The advertised API (DMA-mapping) is what we guarantee to
> support and fixup drivers for.

I don't think that's a good policy. There could be reasons why a driver
might use an internal API .. Breaking the build is worse, to me, than
using an internal API.

> If you don't know that a driver is using an internal API then you can't
> preempt it breaking.  The answer is drivers must not use internal APIs.

At least you need to be receptive to fixes ..

> Had the driver been properly reviewed before being merged, it should
> have been caught before it was merged.

I didn't merge it, so I don't know how it was merged .. Bottom line is
it's a stable kernel driver.

> I've given you the outline of a proper fix, and you've probably already
> spent longer discussing it than it would take you to cut'n'paste the
> code into kernel and test it...

Did you give us a fix for this issue? That's what I was asking in the
last email cause it didn't appear like you touched that area.

Daniel


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