From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Warren <swarren@wwwdotorg.org>
Date: Tue, 15 Mar 2016 09:42:13 -0600
Subject: [U-Boot] [PATCH v3 4/4] usb: Change power-on / scanning timeout
 handling
In-Reply-To: <56E7DA0C.2000202@denx.de>
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 <1457950693-564-5-git-send-email-sr@denx.de> <56E6F555.5020807@wwwdotorg.org>
 <56E7DA0C.2000202@denx.de>
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To: u-boot@lists.denx.de

On 03/15/2016 03:46 AM, Stefan Roese wrote:
> Hi Stephan,
>
> On 14.03.2016 18:31, Stephen Warren wrote:
>> On 03/14/2016 04:18 AM, Stefan Roese wrote:
>>> This patch changes the USB port scanning procedure and timeout
>>> handling in the following ways:

>>> +static int usb_device_list_scan(void)
>> ...
>>> +    static int running;
>>> +    int ret = 0;
>>> +
>>> +    /* Only run this loop once for each controller */
>>> +    if (running)
>>> +        return 0;
>>> +
>>> +    running = 1;
>> ...
>>> +out:
>>> +    /*
>>> +     * This USB controller has has finished scanning all its connected
>>> +     * USB devices. Set "running" back to 0, so that other USB
>>> controllers
>>> +     * will scan their devices too.
>>> +     */
>>> +    running = 0;
>>
>> Doesn't this function only get called a single time from
>> usb_hub_configure()? If so, I don't think the "running" variable is
>> required.
>
> Its called recursively, if hubs are stacked. So its called e.g.
> 5 times in this setup:
>
> => usb tree
> USB device tree:
>    1  Hub (480 Mb/s, 0mA)
>    |  u-boot EHCI Host Controller
>    |
>    +-2  Hub (480 Mb/s, 0mA)
>      |
>      +-3  Hub (480 Mb/s, 100mA)
 >...

Ah right. Mentioning recursion in the variable name or comment would be 
useful.