Re: [PATCH] identify firmware version

From: Dmitry Torokhov
Date: Mon Sep 06 2010 - 19:36:18 EST


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
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