Re: [PATCH] identify firmware version

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Mon, Sep 06, 2010 at 07:32:03PM -0400, Rafi Rubin wrote:
> On Mon, Sep 06, 2010 at 11:22:50PM +0200, Jiri Slaby wrote:
> > 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.
> 
> No arguments from me, that was just sloppy.
> 
> > > 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...
> > 
> > >> +	}
> 
> Jiri, I moved the code to a separate function as Dmitry suggested, and compiled a kernel from a clean tree using 
> gcc-3.4 (I think).
> 
> If this version fails for you, would you mind being a bit more verbose about the failure.
> 

Looks good to me, thanks for making changes Rafi.

-- 
Dmitry