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Message-ID: <19a8be24-0b5c-4232-d3ba-dc7f269bafd3@amd.com>
Date:   Mon, 12 Jun 2023 11:25:20 -0400
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Subject: Re: [PATCH v2] gpu: drm/amd: Remove the redundant null pointer check
 in list_for_each_entry() loops
To:     Lu Hongfei <luhongfei@vivo.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        "open list:AMD KFD" <amd-gfx@lists.freedesktop.org>,
        "open list:DRM DRIVERS" <dri-devel@lists.freedesktop.org>,
        open list <linux-kernel@vger.kernel.org>,
        "Kim, Jonathan" <Jonathan.Kim@amd.com>
Cc:     opensource.kernel@vivo.com
References: <20230612115848.8739-1-luhongfei@vivo.com>
Content-Language: en-US
From:   Felix Kuehling <felix.kuehling@amd.com>
In-Reply-To: <20230612115848.8739-1-luhongfei@vivo.com>
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[+Jon]

Am 2023-06-12 um 07:58 schrieb Lu Hongfei:
> pqn bound in list_for_each_entry loop will not be null, so there is
> no need to check whether pqn is NULL or not.
> Thus remove a redundant null pointer check.
>
> Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
> ---
> The filename of the previous version was:
> 0001-gpu-drm-amd-Fix-the-bug-in-list_for_each_entry-loops.patch
>
> The modifications made compared to the previous version are as follows:
> 1. Modified the patch title
> 2. "Thus remove a redundant null pointer check." is used instead of
>     "We could remove this check."
>
>   drivers/gpu/drm/amd/amdkfd/kfd_debug.c | 3 ---
>   1 file changed, 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
> index cd34e7aaead4..10d0cef844f0 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
> @@ -1097,9 +1097,6 @@ void kfd_dbg_set_enabled_debug_exception_mask(struct kfd_process *target,
>   
>   	pqm = &target->pqm;
>   	list_for_each_entry(pqn, &pqm->queues, process_queue_list) {
> -		if (!pqn)

Right, this check doesn't make a lot of sense. Jon, was this meant to 
check pqn->q?

Regards,
   Felix


> -			continue;
> -
>   		found_mask |= pqn->q->properties.exception_status;
>   	}
>