linux-kernel - Re: [PATCH] clk: qcom: camcc-sc8280xp: Remove always-on GDSC hard-coding

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Message-ID: <86068581-0ce7-47b5-b1c6-fda4f7d1037f@linaro.org>
Date: Wed, 17 Jul 2024 09:49:18 +0100
From: Bryan O'Donoghue <bryan.odonoghue@...aro.org>
To: "Satya Priya Kakitapalli (Temp)" <quic_skakitap@...cinc.com>,
 Bjorn Andersson <andersson@...nel.org>,
 Michael Turquette <mturquette@...libre.com>, Stephen Boyd <sboyd@...nel.org>
Cc: dmitry.baryshkov@...aro.org, stable@...r.kernel.org,
 linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH] clk: qcom: camcc-sc8280xp: Remove always-on GDSC
 hard-coding

On 17/07/2024 07:32, Satya Priya Kakitapalli (Temp) wrote:
> 
> On 7/15/2024 8:29 PM, Bryan O'Donoghue wrote:
>> We have both shared_ops for the Titan Top GDSC and a hard-coded always on
>> whack the register and forget about it in probe().
>>
>> @static struct clk_branch camcc_gdsc_clk = {}
>>
>> Only one representation of the Top GDSC is required. Use the CCF
>> representation not the hard-coded register write.
>>
>> Fixes: ff93872a9c61 ("clk: qcom: camcc-sc8280xp: Add sc8280xp CAMCC")
>> Tested-by: Bryan O'Donoghue <bryan.odonoghue@...aro.org> # Lenovo X13s
>> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@...aro.org>
>> ---
>>   drivers/clk/qcom/camcc-sc8280xp.c | 7 +------
>>   1 file changed, 1 insertion(+), 6 deletions(-)
>>
>> diff --git a/drivers/clk/qcom/camcc-sc8280xp.c 
>> b/drivers/clk/qcom/camcc-sc8280xp.c
>> index 479964f91608..f99cd968459c 100644
>> --- a/drivers/clk/qcom/camcc-sc8280xp.c
>> +++ b/drivers/clk/qcom/camcc-sc8280xp.c
>> @@ -3031,19 +3031,14 @@ static int camcc_sc8280xp_probe(struct 
>> platform_device *pdev)
>>       clk_lucid_pll_configure(&camcc_pll6, regmap, &camcc_pll6_config);
>>       clk_lucid_pll_configure(&camcc_pll7, regmap, &camcc_pll7_config);
>> -    /* Keep some clocks always-on */
>> -    qcom_branch_set_clk_en(regmap, 0xc1e4); /* CAMCC_GDSC_CLK */
> 
> 
> As I mentioned on [1], this change might break the GDSC functionality. 
> Hence this shouldn't be removed.

How would it break ?

We park the clock to XO it never gets turned off this way.

---
bod