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Message-ID: <22d9a9ff-1c44-ed41-6ae1-59a1f965ab6c@collabora.com>
Date:   Thu, 31 Mar 2022 22:41:16 +0300
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Subject: Re: [PATCH v2 10/10] drm/msm: Add a way for userspace to allocate GPU
 iova
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To:     Rob Clark <robdclark@gmail.com>
Cc:     dri-devel <dri-devel@lists.freedesktop.org>,
        freedreno <freedreno@lists.freedesktop.org>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Rob Clark <robdclark@chromium.org>,
        Sean Paul <sean@poorly.run>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Akhil P Oommen <quic_akhilpo@quicinc.com>,
        Jonathan Marek <jonathan@marek.ca>,
        Jordan Crouse <jordan@cosmicpenguin.net>,
        Emma Anholt <emma@anholt.net>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        open list <linux-kernel@vger.kernel.org>
References: <20220330204804.660819-1-robdclark@gmail.com>
 <20220330204804.660819-11-robdclark@gmail.com>
 <ad97096f-cc90-4f20-0f73-f33e9b275f1a@collabora.com>
 <CAF6AEGvZqM1OT_n1C+x+C1GTd4PbFkH4c7P-BseDOUGj7yj3Eg@mail.gmail.com>
From:   Dmitry Osipenko <dmitry.osipenko@collabora.com>
In-Reply-To: <CAF6AEGvZqM1OT_n1C+x+C1GTd4PbFkH4c7P-BseDOUGj7yj3Eg@mail.gmail.com>
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On 3/31/22 22:02, Rob Clark wrote:
> On Thu, Mar 31, 2022 at 11:52 AM Dmitry Osipenko
> <dmitry.osipenko@collabora.com> wrote:
>>
>> ...
>>> +/*
>>> + * Get the requested iova but don't pin it.  Fails if the requested iova is
>>> + * not available.  Doesn't need a put because iovas are currently valid for
>>> + * the life of the object.
>>> + *
>>> + * Setting an iova of zero will clear the vma.
>>> + */
>>> +int msm_gem_set_iova(struct drm_gem_object *obj,
>>> +                  struct msm_gem_address_space *aspace, uint64_t iova)
>>> +{
>>> +     int ret = 0;
>>
>> nit: No need to initialize the ret
> 
> actually, we do

Indeed, sorry :)

...
>>>  int msm_gem_get_and_pin_iova_range(struct drm_gem_object *obj,
>>>               struct msm_gem_address_space *aspace, uint64_t *iova,
>>>               u64 range_start, u64 range_end);
>> nit: There is an odd mix of uint64_t and u64 (and alike) in the MSM code
>> :) The uint64_t variant shouldn't be used by kernel code in general and
>> checkpatch should want about it.
> 
> one of many things that I disagree with checkpatch about ;-)
> 
> I prefer standard types to custom ones.  I _kinda_ get the argument in
> case of uapi (but IMHO that doesn't apply to how drm uapi headers are
> used)

I'd understand if it was all either uint64_t or u64, but the mix.. hm.