Re: [PATCH] identify firmware version

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:

quoted

On 09/06/2010 09:48 PM, Dmitry Torokhov wrote:

quoted

quoted

@@ -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.

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I'd also split all this code into ntrig_report_version() to simplifu
error handling here.

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+
+		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...

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+	}

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