linux-kernel - Re: [PATCH 3/6] dma: dw_dmac: check direction properly in dw_dma_cyclic

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Date:	Fri, 16 Nov 2012 17:30:21 +0200
From:	Andy Shevchenko <andy.shevchenko@...il.com>
To:	balbi@...com
Cc:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Vinod Koul <vinod.koul@...el.com>,
	spear-devel <spear-devel@...t.st.com>,
	linux-kernel@...r.kernel.org,
	Viresh Kumar <viresh.kumar@...aro.org>
Subject: Re: [PATCH 3/6] dma: dw_dmac: check direction properly in dw_dma_cyclic_prep

On Fri, Nov 16, 2012 at 3:56 PM, Felipe Balbi <balbi@...com> wrote:
> On Fri, Nov 16, 2012 at 03:59:16PM +0200, Andy Shevchenko wrote:
>> dma_transfer_direction is a normal enum. It means we can't usually use the
>> values as bit fields. Let's adjust this check and move it above the usage of
>> the direction parameter.
>
> why above the direction parameter ? You need to explain why ? Is it just
> because 'it looks nicer' or have you found another bug triggered by
> that ?

Many of current users do something like this:

if (dir == MEM_TO_DEV)
 { ... }
*else*
 { ... }

that potentially could trigger the bug.

-- 
With Best Regards,
Andy Shevchenko
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