linux-kernel - Re: [PATCH] spi: cadence-qspi: Fix runtime PM imbalance in probe

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Message-ID: <aS9RKnScH2DVXW-I@black.igk.intel.com>
Date: Tue, 2 Dec 2025 21:50:50 +0100
From: Andy Shevchenko <andriy.shevchenko@...el.com>
To: Ali Tariq <alitariq45892@...il.com>
Cc: broonie@...nel.org, linux-spi@...r.kernel.org,
	linux-kernel@...r.kernel.org, khairul.anuar.romli@...era.com,
	adrianhoyin.ng@...era.com, nirav.rabara@...era.com,
	matthew.gerlach@...era.com
Subject: Re: [PATCH] spi: cadence-qspi: Fix runtime PM imbalance in probe

On Sun, Nov 30, 2025 at 09:12:51AM +0000, Ali Tariq wrote:
> The probe function incorrectly calls pm_runtime_put_autosuspend()
> twice in succession at the end of successful probe, dropping two
> runtime PM references while only one was acquired earlier with
> pm_runtime_get_sync(). This causes a usage count underflow:
> 
>     cadence-qspi 13010000.spi: Runtime PM usage count underflow!
> 
> Remove the first redundant pm_runtime_put_autosuspend() call to
> balance the reference count.
> 
> Tested on StarFive VisionFive 2 v1.2A board.

...

>  	if (!(ddata && (ddata->quirks & CQSPI_DISABLE_RUNTIME_PM))) {
> -		pm_runtime_put_autosuspend(dev);
>  		pm_runtime_mark_last_busy(dev);

This one — pm_runtime_mark_last_busy() — also may be removed as it's integrated
into the _put_auutosuspend().

>  		pm_runtime_put_autosuspend(dev);
>  	}

-- 
With Best Regards,
Andy Shevchenko