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Subject: Re: [PATCH 3/3] media: hfi_venus: Request interrupt for sync cmds
To:     Alexandre Courbot <acourbot@chromium.org>
Cc:     linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Vikash Garodia <vgarodia@codeaurora.org>,
        Mansur Alisha Shaik <mansur@codeaurora.org>,
        Dikshita Agarwal <dikshita@codeaurora.org>
References: <20201120001037.10032-1-stanimir.varbanov@linaro.org>
 <20201120001037.10032-4-stanimir.varbanov@linaro.org>
 <CAPBb6MWsaHQtQYh8tQnGjwPCrCXeCnf08jL+yxM9ZkCBFNW5mg@mail.gmail.com>
From:   Stanimir Varbanov <stanimir.varbanov@linaro.org>
Message-ID: <595f8e22-0616-ff8f-78f3-991ef94ebf65@linaro.org>
Date:   Wed, 25 Nov 2020 15:03:46 +0200
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On 11/25/20 10:08 AM, Alexandre Courbot wrote:
> On Fri, Nov 20, 2020 at 9:12 AM Stanimir Varbanov
> <stanimir.varbanov@linaro.org> wrote:
>>
>> From: Vikash Garodia <vgarodia@codeaurora.org>
>>
>> For synchronous commands, update the message queue variable.
>> This would inform video firmware to raise interrupt on host
>> CPU whenever there is a response for such commands.
>>
>> Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>
>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
>> ---
>>  drivers/media/platform/qcom/venus/hfi_venus.c | 74 ++++++++++---------
>>  1 file changed, 41 insertions(+), 33 deletions(-)
>>
>> diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
>> index 4be4a75ddcb6..b8fdb464ba9c 100644
>> --- a/drivers/media/platform/qcom/venus/hfi_venus.c
>> +++ b/drivers/media/platform/qcom/venus/hfi_venus.c
>> @@ -372,7 +372,7 @@ static void venus_soft_int(struct venus_hfi_device *hdev)
>>  }
>>
>>  static int venus_iface_cmdq_write_nolock(struct venus_hfi_device *hdev,
>> -                                        void *pkt)
>> +                                        void *pkt, bool sync)
>>  {
>>         struct device *dev = hdev->core->dev;
>>         struct hfi_pkt_hdr *cmd_packet;
>> @@ -397,15 +397,23 @@ static int venus_iface_cmdq_write_nolock(struct venus_hfi_device *hdev,
>>         if (rx_req)
>>                 venus_soft_int(hdev);
>>
>> +       /* Inform video firmware to raise interrupt for synchronous commands */
>> +       queue = &hdev->queues[IFACEQ_MSG_IDX];
>> +       if (sync) {
>> +               queue->qhdr->rx_req = 1;
>> +               /* ensure rx_req is updated in memory */
>> +               wmb();
>> +       }
> 
> Wouldn't it be safer to do this before calling venus_soft_int()? I
> don't know what the firmware is supposed to do with rx_req but
> intuitively it looks like it should be set before we signal it.
> 

I'll leave Vikash to comment. IMO this is a good suggestion.

<cut>

-- 
regards,
Stan