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Date: Mon, 06 Sep 2010 23:22:50 +0200
From: Jiri Slaby <jirislaby@gmail.com>
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To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: Rafi Rubin <rafi@seas.upenn.edu>, jkosina@suse.cz,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        micki@n-trig.com, rydberg@euromail.se, chatty@enac.fr
Subject: Re: [PATCH] identify firmware version
References: <4C7EB3A3.7050402@gmail.com> <1283791362-27780-1-git-send-email-rafi@seas.upenn.edu> <20100906194838.GB31384@core.coreip.homeip.net>
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On 09/06/2010 09:48 PM, Dmitry Torokhov wrote:
>> @@ -848,10 +871,43 @@ static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
>>  	if (report)
>>  		usbhid_submit_report(hdev, report, USB_DIR_OUT);
>>  
>> +	data = kmalloc(8, GFP_KERNEL);
>> +	if (!data) {
>> +		ret = -ENOMEM;
>> +		goto err_free;
>> +	}
>> +
>> +	ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
>> +			      USB_REQ_CLEAR_FEATURE,
>> +			      USB_TYPE_CLASS | USB_RECIP_INTERFACE |
>> +			      USB_DIR_IN,
>> +			      0x30c, 1, data, 8,
>> +			      USB_CTRL_SET_TIMEOUT);
>> +
>> +	if (ret == 8) {
>> +		buf = kmalloc(20, GFP_KERNEL);
>> +		if (!buf) {
>> +			ret = -ENOMEM;
>> +			goto err_free_data;
>> +		}
> 
> Why do you allocate this from heap? Surely we can spare 20 bytes on
> stack (you aren't doing DMA into it).

Hi, yeah, I think so too.

> I'd also split all this code into ntrig_report_version() to simplifu
> error handling here.
> 
>> +
>> +		ret = ntrig_version_string(&data[2], buf);
>> +
>> +		dev_info(&hdev->dev,
>> +			 "Firmware version: %s (%02x%02x %02x%02x)\n",
>> +			 buf, data[2], data[3], data[4], data[5]);
>> +
>> +		kfree(buff);

In any case, this doesn't compile...

>> +	}

regards,
-- 
js