On 8/23/19 4:19 AM, Linus Walleij wrote:
> On Tue, Aug 20, 2019 at 4:58 PM Dinh Nguyen <dinguyen@xxxxxxxxxx> wrote:
>
>> @@ -401,6 +402,26 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
>> ret = amba_get_enable_pclk(dev);
>> if (ret == 0) {
>> u32 pid, cid;
>> + int count;
>> + struct reset_control *rstc;
>> +
>> + /*
>> + * Find reset control(s) of the amba bus and de-assert them.
>> + */
>> + count = reset_control_get_count(&dev->dev);
>> + while (count > 0) {
>> + rstc = of_reset_control_get_shared_by_index(dev->dev.of_node, count - 1);
>> + if (IS_ERR(rstc)) {
>> + if (PTR_ERR(rstc) == -EPROBE_DEFER)
>> + ret = -EPROBE_DEFER;
>> + else
>> + dev_err(&dev->dev, "Can't get amba reset!\n");
>> + break;
>> + }
>> + reset_control_deassert(rstc);
>> + reset_control_put(rstc);
>> + count--;
>> + }
>
> I'm not normally a footprint person, but the looks of the stubs in
> <linux/reset.h> makes me suspicious whether this will have zero impact
> in size on platforms without reset controllers.
>
> Can you just ls -al on the kernel without CONFIG_RESET_CONTROLLER
> before and after this patch and ascertain that it has zero footprint effect?
Thanks for the review. I checked it, and indeed, it does have a zero
footprint effect.
>
> If it doesn't I'd sure like to break this into its own function and
> stick a if (!IS_ENABLED(CONFIG_RESET_CONTROLLER)) return 0;
> in there to make sure the compiler drops it.
>
> Also it'd be nice to get Philipp's ACK on the semantics, though they
> look correct to me.
>
Dinh
