linux-kernel - [PATCH v5 11/22] thermal/drivers/exynos: convert to use devm_request*_irq

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230721094641.77189-11-frank.li@vivo.com>
Date:   Fri, 21 Jul 2023 17:46:30 +0800
From:   Yangtao Li <frank.li@...o.com>
To:     Bartlomiej Zolnierkiewicz <bzolnier@...il.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Amit Kucheria <amitk@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Alim Akhtar <alim.akhtar@...sung.com>
Cc:     Yangtao Li <frank.li@...o.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        linux-pm@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v5 11/22] thermal/drivers/exynos: convert to use devm_request*_irq_probe()

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@...utronix.de>
Cc: Krzysztof Kozlowski <krzk@...nel.org>
Cc: "Uwe Kleine-König" <u.kleine-koenig@...gutronix.de>
Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>
Cc: AngeloGioacchino Del Regno  <angelogioacchino.delregno@...labora.com>
Signed-off-by: Yangtao Li <frank.li@...o.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
---
 drivers/thermal/samsung/exynos_tmu.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index 45e5c840d130..697d2fbdb1bf 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -1100,12 +1100,11 @@ static int exynos_tmu_probe(struct platform_device *pdev)
 		goto err_sclk;
 	}

-	ret = devm_request_irq(&pdev->dev, data->irq, exynos_tmu_irq,
-		IRQF_TRIGGER_RISING | IRQF_SHARED, dev_name(&pdev->dev), data);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
+	ret = devm_request_irq_probe(&pdev->dev, data->irq, exynos_tmu_irq,
+				     IRQF_TRIGGER_RISING | IRQF_SHARED,
+				     dev_name(&pdev->dev), data, NULL);
+	if (ret)
 		goto err_sclk;
-	}

 	exynos_tmu_control(pdev, true);
 	return 0;
-- 
2.39.0