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Message-ID: <5f749397-d701-a83c-757b-cad38f74735f@wanadoo.fr>
Date:   Wed, 19 Apr 2023 07:28:07 +0200
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Subject: Re: [PATCH] video: fbdev: mmp: Fix deferred clk handling in
 mmphw_probe()
To:     Dan Carpenter <error27@gmail.com>
Cc:     Helge Deller <deller@gmx.de>, Cai Huoqing <cai.huoqing@linux.dev>,
        linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
        linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org
References: <685f452cacc74f4983aaff2bc28a02a95e8aa8b7.1681414375.git.christophe.jaillet@wanadoo.fr>
 <67353089-4966-424c-99c2-8524818f0e37@kili.mountain>
 <a7c75eb0-857c-4755-aa23-0a4a96a6d2ca@kili.mountain>
Content-Language: fr, en-US
From:   Christophe JAILLET <christophe.jaillet@wanadoo.fr>
In-Reply-To: <a7c75eb0-857c-4755-aa23-0a4a96a6d2ca@kili.mountain>
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Precedence: bulk

Le 19/04/2023 à 06:59, Dan Carpenter a écrit :
> On Sat, Apr 15, 2023 at 04:09:03PM +0300, Dan Carpenter wrote:
>> On Thu, Apr 13, 2023 at 09:33:17PM +0200, Christophe JAILLET wrote:
>>> When dev_err_probe() is called, 'ret' holds the value of the previous
>>> successful devm_request_irq() call.
>>> 'ret' should be assigned with a meaningful value before being used in
>>> dev_err_probe().
>>>
>>> While at it, use and return "PTR_ERR(ctrl->clk)" instead of a hard-coded
>>> "-ENOENT" so that -EPROBE_DEFER is handled and propagated correctly.
>>>
>>> Fixes: 81b63420564d ("video: fbdev: mmp: Make use of the helper function dev_err_probe()")
>>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>>> ---
>>
>> Presumably you already wrote a Coccinelle script for this but I've added
>> it to Smatch as well.

No I haven't.
I've spotted it while looking at some devm_clk_get_optional() candidate 
with grep.

	git grep -A5 devm_clk_get | grep -B5 ENOENT

Not perfect, but sometimes this kind of approach can find interesting 
things coccinelle would miss.

As an example, the bitmap_alloc patch on sh4 was found this way, with grep.


So nice to have it in smatch, ;-)

CJ

> 
> Here is this warning:
> drivers/video/fbdev/mmp/hw/mmp_ctrl.c:518 mmphw_probe() warn: passing zero to 'dev_err_probe'
> 
> Other warnings.  All five are interesting.
> drivers/power/supply/rt9467-charger.c:1026 rt9467_request_interrupt() warn: passing zero to 'dev_err_probe'
> drivers/pci/controller/dwc/pcie-bt1.c:601 bt1_pcie_add_port() warn: passing zero to 'dev_err_probe'
> drivers/spi/spi-sprd-adi.c:570 sprd_adi_probe() warn: passing zero to 'dev_err_probe'
> drivers/soc/qcom/icc-bwmon.c:776 bwmon_probe() warn: passing zero to 'dev_err_probe'
> drivers/soc/qcom/icc-bwmon.c:781 bwmon_probe() warn: passing zero to 'dev_err_probe'
> 
> regards,
> dan carpenter
> 
>