linux-kernel - Re: [PATCH 1/2] clk: qcom: videocc: Use HW_CTRL

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Message-ID: <EE235E3C-D327-4483-9C44-DBB72B0DDEA0@linaro.org>
Date: Tue, 26 Nov 2024 09:37:05 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Taniya Das <quic_tdas@...cinc.com>
CC: Renjiang Han <quic_renjiang@...cinc.com>,
 Bjorn Andersson <andersson@...nel.org>,
 Michael Turquette <mturquette@...libre.com>, Stephen Boyd <sboyd@...nel.org>,
 Stanimir Varbanov <stanimir.k.varbanov@...il.com>,
 Vikash Garodia <quic_vgarodia@...cinc.com>,
 Bryan O'Donoghue <bryan.odonoghue@...aro.org>,
 Mauro Carvalho Chehab <mchehab@...nel.org>, linux-arm-msm@...r.kernel.org,
 linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-media@...r.kernel.org
Subject: Re: [PATCH 1/2] clk: qcom: videocc: Use HW_CTRL_TRIGGER flag for video GDSC's

On 26 November 2024 06:04:12 EET, Taniya Das <quic_tdas@...cinc.com> wrote:
>
>
>On 11/23/2024 5:35 AM, Dmitry Baryshkov wrote:
>> On Fri, Nov 22, 2024 at 10:25:44PM +0530, Taniya Das wrote:
>>> 
>>> 
>>> On 11/22/2024 4:29 PM, Dmitry Baryshkov wrote:
>>>> On Fri, Nov 22, 2024 at 04:01:45PM +0530, Renjiang Han wrote:
>>>>> From: Taniya Das <quic_tdas@...cinc.com>
>>>>> 
>>>>> The video driver will be using the newly introduced
>>>> 
>>>> 'will be' or 'is using'? Or will be using it for these platforms? Is
>>>> there any kind of dependency between two patches in the series?
>>>> 
>>> The video driver will not be able to work without the clock side changes.
>> 
>> Will enabling this flag break the video driver until it is updated?
>> 
>
>Yes, my understanding is yes it will break. When we first introduced the flag we had got the driver and the clock changes together.

Please clearly document this in the cover letter. Can venus changes go in first? Or they will also break without the flag? The kernel should not break between commits.

>
>>> 
>>>>> dev_pm_genpd_set_hwmode() API to switch the video GDSC to HW and SW
>>>>> control modes at runtime.
>>>>> Hence use HW_CTRL_TRIGGER flag instead of HW_CTRL for video GDSC's for
>>>>> Qualcomm SoC SC7180 and SDM845.
>>>> 
>>>> Is it applicable to any other platforms? Why did you select just these
>>>> two?
>>>> 
>>> 
>>> The V6 version of Video driver is already using them, now the video driver
>>> wants to migrate to v4 version of the HW to use the new flag.
>> 
>> I mean slightly different issue. We have following drivers:
>> 
>> videocc-sa8775p.c - already uses HW_CTRL_TRIGGER
>> videocc-sc7180.c - being converted now
>> videocc-sc7280.c - already uses HW_CTRL_TRIGGER
>> videocc-sdm845.c - being converted now
>> videocc-sm7150.c
>> videocc-sm8150.c
>> videocc-sm8250.c - already uses HW_CTRL_TRIGGER
>> videocc-sm8350.c - already uses HW_CTRL_TRIGGER
>> videocc-sm8450.c
>> videocc-sm8550.c - already uses HW_CTRL_TRIGGER
>> 
>> This leaves sm7150, sm8150 and sm8450 untouched. Don't they also need to
>> use HW_CTRL_TRIGGER?
>> 
>
>Yes, I am okay to add the flag, but looking for the Video SW team to confirm they are well tested on the rest of the platforms.

Thank you! Let's get confirmation from Vikash or Dikshita.

>
>>> 
>>>>> 
>>>>> Signed-off-by: Taniya Das <quic_tdas@...cinc.com>
>>>>> Signed-off-by: Renjiang Han <quic_renjiang@...cinc.com>
>>>>> ---
>>>>>    drivers/clk/qcom/videocc-sc7180.c | 2 +-
>>>>>    drivers/clk/qcom/videocc-sdm845.c | 4 ++--
>>>>>    2 files changed, 3 insertions(+), 3 deletions(-)
>>>>> 
>>>>> diff --git a/drivers/clk/qcom/videocc-sc7180.c b/drivers/clk/qcom/videocc-sc7180.c
>>>>> index d7f84548039699ce6fdd7c0f6675c168d5eaf4c1..dd2441d6aa83bd7cff17deeb42f5d011c1e9b134 100644
>>>>> --- a/drivers/clk/qcom/videocc-sc7180.c
>>>>> +++ b/drivers/clk/qcom/videocc-sc7180.c
>>>>> @@ -166,7 +166,7 @@ static struct gdsc vcodec0_gdsc = {
>>>>>    	.pd = {
>>>>>    		.name = "vcodec0_gdsc",
>>>>>    	},
>>>>> -	.flags = HW_CTRL,
>>>>> +	.flags = HW_CTRL_TRIGGER,
>>>>>    	.pwrsts = PWRSTS_OFF_ON,
>>>>>    };
>>>>> diff --git a/drivers/clk/qcom/videocc-sdm845.c b/drivers/clk/qcom/videocc-sdm845.c
>>>>> index f77a0777947773dc8902c92098acff71b9b8f10f..6dedc80a8b3e18eca82c08a5bcd7e1fdc374d4b5 100644
>>>>> --- a/drivers/clk/qcom/videocc-sdm845.c
>>>>> +++ b/drivers/clk/qcom/videocc-sdm845.c
>>>>> @@ -260,7 +260,7 @@ static struct gdsc vcodec0_gdsc = {
>>>>>    	},
>>>>>    	.cxcs = (unsigned int []){ 0x890, 0x930 },
>>>>>    	.cxc_count = 2,
>>>>> -	.flags = HW_CTRL | POLL_CFG_GDSCR,
>>>>> +	.flags = HW_CTRL_TRIGGER | POLL_CFG_GDSCR,
>>>>>    	.pwrsts = PWRSTS_OFF_ON,
>>>>>    };
>>>>> @@ -271,7 +271,7 @@ static struct gdsc vcodec1_gdsc = {
>>>>>    	},
>>>>>    	.cxcs = (unsigned int []){ 0x8d0, 0x950 },
>>>>>    	.cxc_count = 2,
>>>>> -	.flags = HW_CTRL | POLL_CFG_GDSCR,
>>>>> +	.flags = HW_CTRL_TRIGGER | POLL_CFG_GDSCR,
>>>>>    	.pwrsts = PWRSTS_OFF_ON,
>>>>>    };
>>>>> 
>>>>> -- 
>>>>> 2.34.1
>>>>> 
>>>> 
>>> 
>>> -- 
>>> Thanks & Regards,
>>> Taniya Das.
>> 
>