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Message-ID: <dde63edb-9057-2d33-032a-8ee25e981c72@ti.com>
Date: Wed, 15 May 2024 09:52:57 +0530
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Subject: Re: [PATCH 1/2] usb: cdns3: Add quirk flag to enable suspend
 residency
Content-Language: en-US
To: Peter Chen <peter.chen@kernel.org>
CC: <pawell@cadence.com>, <rogerq@kernel.org>, <gregkh@linuxfoundation.org>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Ravi Gunasekaran
	<r-gunasekaran@ti.com>
References: <20240514092421.20897-1-r-gunasekaran@ti.com>
 <20240514092421.20897-2-r-gunasekaran@ti.com>
 <20240515013838.GA3279984@nchen-desktop>
From: Ravi Gunasekaran <r-gunasekaran@ti.com>
In-Reply-To: <20240515013838.GA3279984@nchen-desktop>
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On 5/15/24 7:08 AM, Peter Chen wrote:
> On 24-05-14 14:54:20, Ravi Gunasekaran wrote:
>> From: Roger Quadros <rogerq@kernel.org>
>>
>> Some platforms (e.g. ti,j721e-usb, ti,am64-usb) require
>> this bit to be set to workaround a lockup issue with PHY
>> short suspend intervals [1]. Add a platform quirk flag
>> to indicate if Suspend Residency should be enabled.
>>
>> [1] - https://www.ti.com/lit/er/sprz457h/sprz457h.pdf
>> i2409 - USB: USB2 PHY locks up due to short suspend
>>
>> Signed-off-by: Roger Quadros <rogerq@kernel.org>
>> Signed-off-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
>> ---

[...]

>>  	regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
>> @@ -439,6 +439,13 @@ int cdns_drd_init(struct cdns *cdns)
>>  			return -EINVAL;
>>  		}
>>  
>> +		if (cdns->pdata &&
>> +		    (cdns->pdata->quirks & CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE)) {
>> +			reg = readl(&cdns->otg_v1_regs->susp_ctrl);
>> +			reg |= SUSP_CTRL_SUSPEND_RESIDENCY_ENABLE;
>> +			writel(reg, &cdns->otg_v1_regs->susp_ctrl);
>> +		}
>> +
> 
> It is better put this above (just above code cdns->version  =
> CDNS3_CONTROLLER_V1;)
> 

You mean here, to group it with CDNS3 v1?

else if (OTG_CDNS3_CHECK_DID(state)) {                                               
      cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *)
                            &cdns->otg_v1_regs->ien;
      writel(1, &cdns->otg_v1_regs->simulate);

+     if (cdns->pdata &&
+	  (cdns->pdata->quirks & CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE)) {
+	      reg = readl(&cdns->otg_v1_regs->susp_ctrl);
+	      reg |= SUSP_CTRL_SUSPEND_RESIDENCY_ENABLE;
+	      writel(reg, &cdns->otg_v1_regs->susp_ctrl);
+     }
      dns->version  = CDNS3_CONTROLLER_V1;
} else

> Peter
>>  		dev_dbg(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
>>  			 readl(&cdns->otg_v1_regs->did),
>>  			 readl(&cdns->otg_v1_regs->rid));
>> diff --git a/drivers/usb/cdns3/drd.h b/drivers/usb/cdns3/drd.h
>> index d72370c321d3..1e2aee14d629 100644
>> --- a/drivers/usb/cdns3/drd.h
>> +++ b/drivers/usb/cdns3/drd.h
>> @@ -193,6 +193,9 @@ struct cdns_otg_irq_regs {
>>  /* OTGREFCLK - bitmasks */
>>  #define OTGREFCLK_STB_CLK_SWITCH_EN	BIT(31)
>>  
>> +/* SUPS_CTRL - bitmasks */
>> +#define SUSP_CTRL_SUSPEND_RESIDENCY_ENABLE	BIT(17)
>> +
>>  /* OVERRIDE - bitmasks */
>>  #define OVERRIDE_IDPULLUP		BIT(0)
>>  /* Only for CDNS3_CONTROLLER_V0 version */
>> -- 
>> 2.17.1
>>
> 

-- 
Regards,
Ravi