[U-Boot] [PATCH v6] cmd: usb: ignore blk, emulation devices in usb tree/info display

[Bin Meng]

Hi Marek,

On Thu, Oct 19, 2017 at 3:33 PM, Marek Vasut <marex at denx.de> wrote:
> On 10/19/2017 05:24 AM, Suneel Garapati wrote:
>> On Wed, Oct 18, 2017 at 6:39 PM, Marek Vasut <marex at denx.de> wrote:
>>> On 10/19/2017 03:22 AM, Suneel Garapati wrote:
>>>> usb tree/info commands iterate over all usb uclass devices
>>>> recursively. blk uclass child devices are created for mass storage,
>>>> treating these as usb uclass devices and referencing usb config
>>>> interface descriptors cause crash. To fix, ignore blk and usb_emul
>>>> uclass devices(sandbox)
>>>                  ^^^^^^^ what's this about ? USB_EMUL devices can be
>>> enables elsewhere too, right ?
>> Only disabled during the tree/info dump.
>
> I don't understand this answer. Can USB_EMUL devices be enabled on any
> other machine than sandbox or not ? I presume it can ...
>

No, it cannot.

>>> Anyway, shouldn't you rather filter for positive matches (usb uclass
>>> devices etc) , rather than filtering out a few negative matches (blk
>>> etc) which might break in the future ?
>> usb_for_each_root_dev does that but we dont have uclass_find_first_child_device
>> to call on UCLASS_USB like uclass_find_first_device.
>> So, device_find_first_child and check on uclass id is performed.
>
> I mean, rather than doing
> (device_get_uclass_id(child) != UCLASS_USB_xxx &&
> device_get_uclass_id(child) != UCLASS_USB_yyy)
>    dump
>
> do
>
> (device_get_uclass_id(child) == UCLASS_USB_nnn)
>    dump
>
> for nnn being only the relevant USB classes for which we actually want
> to dump.
>
> Does that work ?
>

No, I don't think you can enumerate all USB devices here. It can be
any uclass device.

>>>> in usb_show_info and usb_tree_graph.
>>>> also avoid addition of preamble for blk uclass child devices,
>>>> otherwise tree dump gets messed up.
>>>
>>> Also, sentences start with capital letter. This should be in a separate
>>> patch if it's a separate change ...
>> Ignoring preamble and device should go together, hence cannot be
>> separate change.
>>

[snip]

Regards,
Bin