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Subject: Re: [PATCH v11 4/5] usb: dwc3: dwc3-qcom: Enable tx-fifo-resize
 property by default
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     robh+dt@kernel.org, agross@kernel.org, bjorn.andersson@linaro.org,
        balbi@kernel.org, linux-usb@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, jackp@codeaurora.org,
        fntoth@gmail.com
References: <1625043642-29822-1-git-send-email-wcheng@codeaurora.org>
 <1625043642-29822-5-git-send-email-wcheng@codeaurora.org>
 <YN6e8G1e9cZBBMr7@kroah.com>
From:   Wesley Cheng <wcheng@codeaurora.org>
Message-ID: <83237faa-9840-5d31-43da-8ce551e75067@codeaurora.org>
Date:   Fri, 2 Jul 2021 01:10:13 -0700
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On 7/1/2021 10:06 PM, Greg KH wrote:
> On Wed, Jun 30, 2021 at 02:00:41AM -0700, Wesley Cheng wrote:
>> In order to take advantage of the TX fifo resizing logic, manually add
>> these properties to the DWC3 child node by default.  This will allow
>> the DWC3 gadget to resize the TX fifos for the IN endpoints, which
>> help with performance.
>>
>> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
>> ---
>>  drivers/usb/dwc3/dwc3-qcom.c | 21 +++++++++++++++++++++
>>  1 file changed, 21 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
>> index 49e6ca9..cec4f4a 100644
>> --- a/drivers/usb/dwc3/dwc3-qcom.c
>> +++ b/drivers/usb/dwc3/dwc3-qcom.c
>> @@ -640,6 +640,25 @@ static int dwc3_qcom_acpi_register_core(struct platform_device *pdev)
>>  	return ret;
>>  }
>>  
>> +#ifdef CONFIG_OF
>> +static void dwc3_qcom_add_dt_props(struct device *dev, struct device_node *np)
>> +{
>> +	struct property		*prop;
>> +	int ret;
>> +
>> +	prop = devm_kzalloc(dev, sizeof(*prop), GFP_KERNEL);
>> +	if (prop) {
>> +		prop->name = "tx-fifo-resize";
>> +		ret = of_add_property(np, prop);
>> +		if (ret < 0)
>> +			dev_info(dev, "unable to add tx-fifo-resize prop\n");

Hi Greg,
> 
> Is that really an "informational" error?  :(
> 
>
We can remove it.  If anything we can always check the sysfs if the
property is present or not.

>> +	}
> 
> So if you can not allocate memory, you just fail quietly?  Are you sure
> that is ok?
> 
> Please properly handle errors.
> 
OK, will handle the case where we can't allocate memory for the property.

Thanks
Wesley Cheng

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