Re: [v5, 2/6] fsl/fman: Add FMan support

On Thu, Sep 24, 2015 at 12:10:34PM +0300, igal.liberman@freescale.com wrote:

+int fman_get_rx_extra_headroom(void)
+{
+	static bool fm_check_rx_extra_headroom;
+
+	if (!fm_check_rx_extra_headroom) {
+		if (fsl_fm_rx_extra_headroom > FSL_FM_RX_EXTRA_HEADROOM_MAX ||
+		    fsl_fm_rx_extra_headroom < FSL_FM_RX_EXTRA_HEADROOM_MIN) {
+			pr_warn("Invalid fsl_fm_rx_extra_headroom value (%d) in bootargs, valid range is %d-%d. Falling back to the default (%d)\n",
+				fsl_fm_rx_extra_headroom,
+				FSL_FM_RX_EXTRA_HEADROOM_MIN,
+				FSL_FM_RX_EXTRA_HEADROOM_MAX,
+				FSL_FM_RX_EXTRA_HEADROOM);
+			fsl_fm_rx_extra_headroom = FSL_FM_RX_EXTRA_HEADROOM;
+		}
+
+		fsl_fm_rx_extra_headroom = true;

I think you mean "fm_check_rx_extra_headroom = true".

+		fsl_fm_rx_extra_headroom = ALIGN(fsl_fm_rx_extra_headroom, 16);
+	}
+
+	return fsl_fm_rx_extra_headroom;
+}
+EXPORT_SYMBOL(fman_get_rx_extra_headroom);

Please just check things like this once during module init. 
Init-on-first-use is unnecessarily complicated, and race-prone.

-Scott