Re: [PATCH] gpu: host1x: fix uninitialized variable use

From: Mikko Perttunen <cyndis@kapsi.fi>
To: Nathan Chancellor <nathan@kernel.org>, Arnd Bergmann <arnd@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	Arnd Bergmann <arnd@arndb.de>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Tom Rix <trix@redhat.com>,
	Mikko Perttunen <mperttunen@nvidia.com>,
	Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	Robin Murphy <robin.murphy@arm.com>,
	dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH] gpu: host1x: fix uninitialized variable use
Date: Sat, 28 Jan 2023 10:12:15 +0200	[thread overview]
Message-ID: <46a462ec-bc80-cbb7-4833-d9c430f4e9c3@kapsi.fi> (raw)
In-Reply-To: <Y9RbvPRP5Yw/fUMM@dev-arch.thelio-3990X>

On 1/28/23 01:18, Nathan Chancellor wrote:
> On Fri, Jan 27, 2023 at 11:14:00PM +0100, Arnd Bergmann wrote:
>> From: Arnd Bergmann <arnd@arndb.de>
>>
>> The error handling for platform_get_irq() failing no longer
>> works after a recent change, clang now points this out with
>> a warning:
>>
>> drivers/gpu/host1x/dev.c:520:6: error: variable 'syncpt_irq' is uninitialized when used here [-Werror,-Wuninitialized]
>>          if (syncpt_irq < 0)
>>              ^~~~~~~~~~
>>
>> Fix this by removing the variable and checking the correct
>> error status.
>>
>> Fixes: 625d4ffb438c ("gpu: host1x: Rewrite syncpoint interrupt handling")
>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> I had the same diff pending but civic duty called today :)
> 
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
> 
>> ---
>>   drivers/gpu/host1x/dev.c | 5 ++---
>>   1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
>> index 4872d183d860..aae2efeef503 100644
>> --- a/drivers/gpu/host1x/dev.c
>> +++ b/drivers/gpu/host1x/dev.c
>> @@ -487,7 +487,6 @@ static int host1x_get_resets(struct host1x *host)
>>   static int host1x_probe(struct platform_device *pdev)
>>   {
>>   	struct host1x *host;
>> -	int syncpt_irq;
>>   	int err;
>>   
>>   	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
>> @@ -517,8 +516,8 @@ static int host1x_probe(struct platform_device *pdev)
>>   	}
>>   
>>   	host->syncpt_irq = platform_get_irq(pdev, 0);
>> -	if (syncpt_irq < 0)
>> -		return syncpt_irq;
>> +	if (host->syncpt_irq < 0)
>> +		return host->syncpt_irq;
>>   
>>   	mutex_init(&host->devices_lock);
>>   	INIT_LIST_HEAD(&host->devices);
>> -- 
>> 2.39.0
>>

Thanks both for the fix :)

FWIW,

Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>