Re: [PATCH v4 12/21] thermal/drivers/rockchip: convert to use devm_request*_irq_probe()

From: Heiko Stuebner <heiko@sntech.de>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Kucheria <amitk@kernel.org>, Zhang Rui <rui.zhang@intel.com>,
	Yangtao Li <frank.li@vivo.com>
Cc: "Yangtao Li" <frank.li@vivo.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Krzysztof Kozlowski" <krzk@kernel.org>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Jonathan Cameron" <Jonathan.Cameron@huawei.com>,
	"AngeloGioacchino Del Regno"
	<angelogioacchino.delregno@collabora.com>,
	linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 12/21] thermal/drivers/rockchip: convert to use devm_request*_irq_probe()
Date: Mon, 10 Jul 2023 13:05:42 +0200	[thread overview]
Message-ID: <2114204.OBFZWjSADL@phil> (raw)
In-Reply-To: <20230710095926.15614-12-frank.li@vivo.com>

Am Montag, 10. Juli 2023, 11:59:16 CEST schrieb Yangtao Li:
> There are more than 700 calls to devm_request_threaded_irq method and
> more than 1000 calls to devm_request_irq method. Most drivers only
> request one interrupt resource, and these error messages are basically
> the same. If error messages are printed everywhere, more than 2000 lines
> of code can be saved by removing the msg in the driver.
> 
> And tglx point out that:
> 
>   If we actually look at the call sites of
>   devm_request_threaded_irq() then the vast majority of them print more or
>   less lousy error messages. A quick grep/sed/awk/sort/uniq revealed
> 
>      519 messages total (there are probably more)
> 
>      352 unique messages
> 
>      323 unique messages after lower casing
> 
>          Those 323 are mostly just variants of the same patterns with
>          slight modifications in formatting and information provided.
> 
>      186 of these messages do not deliver any useful information,
>          e.g. "no irq", "
> 
>      The most useful one of all is: "could request wakeup irq: %d"
> 
>   So there is certainly an argument to be made that this particular
>   function should print a well formatted and informative error message.
> 
>   It's not a general allocator like kmalloc(). It's specialized and in the
>   vast majority of cases failing to request the interrupt causes the
>   device probe to fail. So having proper and consistent information why
>   the device cannot be used _is_ useful.
> 
> So convert to use devm_request*_irq_probe() API, which ensure that all
> error handling branches print error information.
> 
> In this way, when this function fails, the upper-layer functions can
> directly return an error code without missing debugging information.
> Otherwise, the error message will be printed redundantly or missing.
> 
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Krzysztof Kozlowski <krzk@kernel.org>
> Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
> Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
> Cc: AngeloGioacchino Del Regno  <angelogioacchino.delregno@collabora.com>
> Signed-off-by: Yangtao Li <frank.li@vivo.com>

Acked-by: Heiko Stuebner <heiko@sntech.de>


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