linux-kernel - Re: [PATCH v2 2/2] mtd: nand: raw: gpmi: improve power management handling

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Message-ID: <20241003172820.50324192@xps-13>
Date: Thu, 3 Oct 2024 17:28:20 +0200
From: Miquel Raynal <miquel.raynal@...tlin.com>
To: Han Xu <han.xu@....com>
Cc: Richard Weinberger <richard@....at>, Vignesh Raghavendra
 <vigneshr@...com>, imx@...ts.linux.dev, linux-mtd@...ts.infradead.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] mtd: nand: raw: gpmi: improve power management
 handling

Hi Han,

han.xu@....com wrote on Thu, 3 Oct 2024 10:05:16 -0500:

> On 24/10/03 09:38AM, Miquel Raynal wrote:
> > Hi Han,
> > 
> > han.xu@....com wrote on Wed,  2 Oct 2024 10:39:44 -0500:
> >   
> > > The commit refactors the power management handling in the gpmi nand
> > > driver. It removes redundant pm_runtime calls in the probe function,
> > > handles the pad control in suspend and resume, and moves the calls to
> > > acquire and release DMA channels to the runtime suspend and resume
> > > functions.  
> > 
> > May I know the motivation to acquire and release the DMA channels
> > during suspend? In general it seems like a different change which I'd
> > prefer to see in its own commit with a justification. The rest looks
> > ok otherwise.  
> 
> Hi Miquel,
> 
> Thanks for your comments. IMHO there is no much logic changes indeed, just move
> the dma channel acquire and release from system pm to the runtime pm, releasing
> the unused resources as early as possible. If you think it's necessary I will
> split the patch into two parts.

Actually I don't understand why these channels are released and
acquired again. Does it make sense to do that in the (runtime)
suspend/resume path? I'd be in favor of avoiding this extra
configuration which as a first sight does not seem required here.

Thanks,
Miquèl