Re: [PATCH v2 5/5] simplefb: add clock handling code

On Fri, Oct 3, 2014 at 1:52 PM, Hans de Goede [off-list ref] wrote:

+static void
+simplefb_clocks_init(struct platform_device *pdev, struct list_head *list)
+{
+       struct device_node *np = pdev->dev.of_node;
+       int clock_count, i;
+
+       INIT_LIST_HEAD(list);
+
+       if (dev_get_platdata(&pdev->dev) || !np)
+               return;
+
+       clock_count = of_clk_get_parent_count(np);
+       for (i = 0; i < clock_count; i++) {
+               struct simplefb_clock *entry;
+               struct clk *clock = of_clk_get(np, i);
+               int ret;
+
+               if (IS_ERR(clock)) {
+                       dev_err(&pdev->dev, "%s: clock %d not found: %ld\n",
+                              __func__, i, PTR_ERR(clock));
+                       continue;
+               }
+
+               ret = clk_prepare_enable(clock);
+               if (ret) {
+                       dev_err(&pdev->dev,
+                               "%s: failed to enable clock %d: %d\n",
+                              __func__, i, ret);
+                       clk_put(clock);
+                       continue;
+               }
+
+               entry = kzalloc(sizeof(struct simplefb_clock), GFP_KERNEL);
+               if (!entry) {
+                       clk_disable_unprepare(clock);
+                       clk_put(clock);
+                       continue;
+               }

I'd allocate memory first, to avoid calling clk_disable_unprepare() (which
will kill your display) if memory allocation fails.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds