diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index dc8d39ae045b..9c7679c06dca 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -1219,10 +1219,12 @@ static int sunxi_pinctrl_build_state(struct platform_device *pdev)
 	}
 
 	/*
-	 * We suppose that we won't have any more functions than pins,
-	 * we'll reallocate that later anyway
+	 * Find an upper bound for the maximum number of functions: in
+	 * the worst case we have gpio_in, gpio_out, irq and up to four
+	 * special functions per pin, plus one entry for the sentinel.
+	 * We'll reallocate that later anyway.
 	 */
-	pctl->functions = kcalloc(pctl->ngroups,
+	pctl->functions = kcalloc(4 * pctl->ngroups + 4,
 				  sizeof(*pctl->functions),
 				  GFP_KERNEL);
 	if (!pctl->functions)