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Message-ID: <7d904044-05da-4671-b8de-e752b952b006@quicinc.com>
Date: Fri, 31 May 2024 08:50:30 +0530
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Subject: Re: [PATCH V2] cpufreq: scmi: Avoid overflow of target_freq in fast
 switch
To: Viresh Kumar <viresh.kumar@linaro.org>
CC: Sudeep Holla <sudeep.holla@arm.com>,
        "Rafael J . Wysocki"
	<rafael@kernel.org>,
        Cristian Marussi <cristian.marussi@arm.com>,
        <linux-arm-kernel@lists.infradead.org>, <linux-pm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, Taniya Das <quic_tdas@quicinc.com>,
        "Ajit
 Pandey" <quic_ajipan@quicinc.com>,
        Imran Shaik <quic_imrashai@quicinc.com>,
        Vivek Aknurwar <quic_viveka@quicinc.com>,
        Mike Tipton
	<quic_mdtipton@quicinc.com>
References: <20240520063732.11220-1-quic_jkona@quicinc.com>
 <20240520084744.sb2rk7l2pjf4whyd@vireshk-i7>
 <e3a7c295-28e8-465c-824f-6f14c5977726@quicinc.com>
 <20240528040345.ghw6qkha3cka2pe5@vireshk-i7>
Content-Language: en-US
From: Jagadeesh Kona <quic_jkona@quicinc.com>
In-Reply-To: <20240528040345.ghw6qkha3cka2pe5@vireshk-i7>
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On 5/28/2024 9:33 AM, Viresh Kumar wrote:
> On 27-05-24, 15:26, Jagadeesh Kona wrote:
>>
>>
>> On 5/20/2024 2:17 PM, Viresh Kumar wrote:
>>> On 20-05-24, 12:07, Jagadeesh Kona wrote:
>>>> Conversion of target_freq to HZ in scmi_cpufreq_fast_switch()
>>>> can lead to overflow if the multiplied result is greater than
>>>> UINT_MAX, since type of target_freq is unsigned int. Avoid this
>>>> overflow by assigning target_freq to unsigned long variable for
>>>> converting it to HZ.
>>>>
>>>> Signed-off-by: Jagadeesh Kona <quic_jkona@quicinc.com>
>>>> ---
>>>> Changes in V2:
>>>>     - Updated freq variable from u64 to unsigned long to keep it
>>>>       consistent with the rate parameter in scmi .freq_set() callback
>>>>     - Link to v1: https://lore.kernel.org/all/20240517070157.19553-1-quic_jkona@quicinc.com/
>>>> ---
>>>>    drivers/cpufreq/scmi-cpufreq.c | 4 ++--
>>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> Applied. Thanks.
>>>
>>
>> Thanks Viresh for the offline update on applying this patch to cpufreq arm
>> tree. Please help share the git tree details of the same, since we need them
>> to pick this change in Google ACK and downstream tree.
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm.git cpufreq/arm/linux-next
> 
> I have pushed it out now, it will be there in linux-next soon. My
> branch is not fixed, I may end up rebasing it. Ideally, you shouldn't
> backport anything to android unless it end ups in Linus's tree, only
> then the sha id will be fixed and guaranteed not to change.
> 

Thanks Viresh!