linux-kernel - Re: [PATCH 0/7] clk: qcom: gcc: Do not turn off PCIe GDSCs during gdsc

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Message-ID: <500313f1-51fd-450e-877e-e4626b7652bc@oss.qualcomm.com>
Date: Fri, 2 Jan 2026 12:39:55 +0100
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd
 <sboyd@...nel.org>, Taniya Das <quic_tdas@...cinc.com>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Bartosz Golaszewski
 <brgl@...nel.org>,
        Shazad Hussain <quic_shazhuss@...cinc.com>,
        Sibi Sankar <sibi.sankar@....qualcomm.com>,
        Bryan O'Donoghue <bryan.odonoghue@...aro.org>,
        Melody Olvera <quic_molvera@...cinc.com>,
        Dmitry Baryshkov
 <lumag@...nel.org>,
        Taniya Das <taniya.das@....qualcomm.com>,
        Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>,
        Imran Shaik <quic_imrashai@...cinc.com>,
        Abel Vesa <abelvesa@...nel.org>
Cc: linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Rajendra Nayak <quic_rjendra@...cinc.com>,
        manivannan.sadhasivam@....qualcomm.com, stable@...r.kernel.org
Subject: Re: [PATCH 0/7] clk: qcom: gcc: Do not turn off PCIe GDSCs during
 gdsc_disable()

On 1/2/26 12:36 PM, Krishna Chaitanya Chundru wrote:
> 
> 
> On 1/2/2026 5:04 PM, Konrad Dybcio wrote:
>> On 1/2/26 10:43 AM, Krishna Chaitanya Chundru wrote:
>>> With PWRSTS_OFF_ON, PCIe GDSCs are turned off during gdsc_disable(). This
>>> can happen during scenarios such as system suspend and breaks the resume
>>> of PCIe controllers from suspend.
>> Isn't turning the GDSCs off what we want though? At least during system
>> suspend?
> If we are keeping link in D3cold it makes sense, but currently we are not keeping in D3cold
> so we don't expect them to get off.

Since we seem to be tackling that in parallel, it seems to make sense
that adding a mechanism to let the PCIe driver select "on" vs "ret" vs
"off" could be useful for us

FWIW I recall I could turn off the GDSCs on at least makena with the old
suspend patches and the controllers would come back to life afterwards

Konrad