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Message-ID: <3b8371b1-8b09-dc4b-bb8f-231a6ed53288@quicinc.com>
Date:   Wed, 15 Jun 2022 18:44:55 +0530
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Subject: Re: [PATCH v1] PCI: qcom: Allow L1 and its sub states on qcom dwc
 wrapper
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To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
CC:     <helgaas@kernel.org>, <linux-pci@vger.kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_vbadigan@quicinc.com>, <quic_hemantk@quicinc.com>,
        <quic_ramkri@quicinc.com>, <swboyd@chromium.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        "Stanimir Varbanov" <svarbanov@mm-sol.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        =?UTF-8?Q?Krzysztof_Wilczy=c5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>
References: <1654240730-31322-1-git-send-email-quic_krichai@quicinc.com>
 <20220609112630.GG2758@thinkpad>
From:   Krishna Chaitanya Chundru <quic_krichai@quicinc.com>
In-Reply-To: <20220609112630.GG2758@thinkpad>
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On 6/9/2022 4:56 PM, Manivannan Sadhasivam wrote:
> On Fri, Jun 03, 2022 at 12:48:50PM +0530, Krishna chaitanya chundru wrote:
>> Allow L1 and its sub-states in the qcom dwc pcie wrapper.
> s/wrapper/driver
>
> Also there is no need to use "qcom dwc" in subject. Prefix makes it explicit.
Sure will update in the next patch.
>> By default its disabled. So enable it explicitly.
>>
>> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
>> ---
>>   drivers/pci/controller/dwc/pcie-qcom.c | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>> index 6ab9089..f60645c 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -41,6 +41,9 @@
>>   #define L23_CLK_RMV_DIS				BIT(2)
>>   #define L1_CLK_RMV_DIS				BIT(1)
>>   
>> +#define PCIE20_PARF_PM_CTRL			0x20
>> +#define REQ_NOT_ENTR_L1				BIT(5)
>> +
>>   #define PCIE20_PARF_PHY_CTRL			0x40
>>   #define PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK	GENMASK(20, 16)
>>   #define PHY_CTRL_PHY_TX0_TERM_OFFSET(x)		((x) << 16)
>> @@ -1267,6 +1270,11 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
>>   	val |= BIT(4);
>>   	writel(val, pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
>>   
>> +	/* Clear PARF PM REQ_NOT_ENTR_L1 bit to allow L1 states */
> Mentioning the field in comment is redundant. Just say "Enable L1 and L1ss"
sure will update in the next patch.
> Thanks,
> Mani
>
>> +	val = readl(pcie->parf + PCIE20_PARF_PM_CTRL);
>> +	val &= ~REQ_NOT_ENTR_L1;
>> +	writel(val, pcie->parf + PCIE20_PARF_PM_CTRL);
>> +
>>   	if (IS_ENABLED(CONFIG_PCI_MSI)) {
>>   		val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
>>   		val |= BIT(31);
>> -- 
>> 2.7.4
>>