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Subject: Re: [PATCH 08/10] venus: vdec_ctrls: get real minimum buffers for
 capture
To:     Alexandre Courbot <acourbot@chromium.org>
Cc:     Linux Media Mailing List <linux-media@vger.kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-arm-msm@vger.kernel.org,
        Vikash Garodia <vgarodia@codeaurora.org>,
        Tomasz Figa <tfiga@chromium.org>,
        Malathi Gottam <mgottam@codeaurora.org>
References: <20190117162008.25217-1-stanimir.varbanov@linaro.org>
 <20190117162008.25217-9-stanimir.varbanov@linaro.org>
 <CAPBb6MWJXWLcGh3dbejiYzyqT6OB1_FN6zrcZFO5DbxqXSAWjQ@mail.gmail.com>
From:   Stanimir Varbanov <stanimir.varbanov@linaro.org>
Message-ID: <c9ce287b-e064-9fbe-6ee0-176253e0de84@linaro.org>
Date:   Thu, 24 Jan 2019 11:59:01 +0200
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Hi Alex,

Thanks for the comments!

On 1/24/19 10:43 AM, Alexandre Courbot wrote:
> On Fri, Jan 18, 2019 at 1:21 AM Stanimir Varbanov
> <stanimir.varbanov@linaro.org> wrote:
>>
>> Until now we returned num_output_bufs set during reqbuf but
>> that could be wrong when we implement stateful Codec API. So
>> get the minimum buffers for capture from HFI. This is supposed
>> to be called after stream header parsing, i.e. after dequeue
>> v4l2 event for change resolution.
>>
>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
>> ---
>>  drivers/media/platform/qcom/venus/vdec_ctrls.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/platform/qcom/venus/vdec_ctrls.c b/drivers/media/platform/qcom/venus/vdec_ctrls.c
>> index f4604b0cd57e..e1da87bf52bc 100644
>> --- a/drivers/media/platform/qcom/venus/vdec_ctrls.c
>> +++ b/drivers/media/platform/qcom/venus/vdec_ctrls.c
>> @@ -16,6 +16,7 @@
>>  #include <media/v4l2-ctrls.h>
>>
>>  #include "core.h"
>> +#include "helpers.h"
>>  #include "vdec.h"
>>
>>  static int vdec_op_s_ctrl(struct v4l2_ctrl *ctrl)
>> @@ -47,7 +48,9 @@ static int vdec_op_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
>>  {
>>         struct venus_inst *inst = ctrl_to_inst(ctrl);
>>         struct vdec_controls *ctr = &inst->controls.dec;
>> +       struct hfi_buffer_requirements bufreq;
>>         union hfi_get_property hprop;
>> +       enum hfi_version ver = inst->core->res->hfi_version;
>>         u32 ptype = HFI_PROPERTY_PARAM_PROFILE_LEVEL_CURRENT;
>>         int ret;
>>
>> @@ -71,7 +74,9 @@ static int vdec_op_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
>>                 ctrl->val = ctr->post_loop_deb_mode;
>>                 break;
>>         case V4L2_CID_MIN_BUFFERS_FOR_CAPTURE:
>> -               ctrl->val = inst->num_output_bufs;
>> +               ret = venus_helper_get_bufreq(inst, HFI_BUFFER_OUTPUT, &bufreq);
>> +               if (!ret)
>> +                       ctrl->val = HFI_BUFREQ_COUNT_MIN(&bufreq, ver);
> 
> What happens if venus_helper_get_bufreq() returns an error? It seems
> that we just happily continue with whatever the previous value of
> ctrl->val was. It seems like we do the same with other controls as
> well.

I agree that this is wrong, I think no-one userspace client used that
g_ctrls controls :)

> 
> I think you can fix this globally by initializing ret to 0 at the
> beginning of the function, and then returning ret instead of 0 at the
> end. That way all errors would be propagated. Of course please check
> that this is relevant for other controls following this scheme before
> doing so. :)
> 

yes, I will do!

-- 
regards,
Stan