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Date: Thu, 18 Apr 2024 18:52:46 +0300
From: Serge Semin <fancer.lancer@gmail.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Viresh Kumar <vireshk@kernel.org>, Vinod Koul <vkoul@kernel.org>, 
	Ilpo =?utf-8?B?SsOkcnZpbmVu?= <ilpo.jarvinen@linux.intel.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, 
	Jiri Slaby <jirislaby@kernel.org>, dmaengine@vger.kernel.org, linux-serial@vger.kernel.org, 
	linux-kernel@vger.kernel.org, Viresh Kumar <viresh.kumar@linaro.org>
Subject: Re: [PATCH 2/4] dmaengine: dw: Add memory bus width verification
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On Thu, Apr 18, 2024 at 12:37:09PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 17, 2024 at 09:52:42PM +0300, Serge Semin wrote:
> > On Wed, Apr 17, 2024 at 08:28:06PM +0300, Andy Shevchenko wrote:
> > > On Wed, Apr 17, 2024 at 08:13:59PM +0300, Serge Semin wrote:
> 
> ...
> 
> > > Got it. Maybe a little summary in the code to explain all this magic?
> > 
> > Will it be enough to add something like this:
> > /*
> >  * It's possible to have a data portion locked in the DMA FIFO in case
> >  * of the channel suspension. Subsequent channel disabling will cause
> >  * that data silent loss. In order to prevent that maintain the src
> >  * and dst transfer widths coherency by means of the relation:
> >  * (CTLx.SRC_TR_WIDTH * CTLx.SRC_MSIZE >= CTLx.DST_TR_WIDTH)
> >  */
> 
> Yes, and you may add something like
> "Look for the details in the commit message that brings this change."
> at the end of it.

Agreed. Thanks.

-Serge(y)

> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
>