[U-Boot] [PATCH] musb: set MUSB speed based on CONFIG

[Heiko Schocher <hs@denx.de>]

Hello Bin Liu,

Am 10.07.2015 um 17:31 schrieb Bin Liu:
> Hi,
>
> On 07/10/2015 10:12 AM, Heiko Schocher wrote:
>> Hello Samuel,
>>
>> Am 10.07.2015 um 16:50 schrieb Egli, Samuel:
>>> Hi Hans,
>>>
>>>> -----Original Message----- From: Hans de Goede
>>>> [mailto:hdegoede at redhat.com] Sent: Freitag, 10. Juli 2015 16:37
>>>> To: Egli, Samuel; marex at denx.de Cc: u-boot at lists.denx.de;
>>>> trini at konsulko.com; Bin Liu; Meier, Roger; Daniel Mack Subject:
>>>> Re: [U-Boot] [PATCH] musb: set MUSB speed based on CONFIG
>>>>
>>>> Hi,
>>>>
>>>> On 10-07-15 16:30, Hans de Goede wrote:
>>>>> Hi,
>>>>>
>>>>> On 10-07-15 15:16, Samuel Egli wrote:
>>>>>> From: Bin Liu <b-liu@ti.com>
>>>>>>
>>>>>> Do not config MUSB to highspeed mode if
>>>>>> CONFIG_USB_GADGET_DUALSPEED is not set, in which case Ether
>>>>>> gadget only operates in fullspeed.
>>>>>>
>>>>>> Note: This patch is necessary for devices like some siemens
>>>>>> boards that allow only FULL SPEED USB 1.1, e.g. DFU
>>>>>> download.
>>>>>>
>>>>>> Signed-off-by: Bin Liu <b-liu@ti.com> Reviewed-by: Tom Rini
>>>>>> <trini@konsulko.com> Tested-by: Samuel Egli
>>>>>> <samuel.egli@siemens.com> CC: Marek Vasut <marex@denx.de> CC:
>>>>>> Heiko Schocher <hs@denx.de> CC: Daniel Mack
>>>>>> <zonque@gmail.com> CC: Roger Meier <r.meier@siemens.com>
>>>>>
>>>>> Nack this breaks highspeed mode on boards which use the musb in
>>>>> host mode, and thus do not set CONFIG_USB_GADGET_DUALSPEED.
>
> My bad, I had a short thought about this when I was initially working on
> this patch, but did not really think about it throughly. Thanks for
> bring it up.
>
>>>>
>>>> p.s.
>>>>
>>>> Given that you want to use this as a hack to work around the
>>>> broken pcb design of your board I suggest adding a new option for
>>>> this
>>>
>>> Well, lets not discuss the "broken" pcb design. It seems that
>>> wiring protection is not that common. Unfortunately, such a
>>> protection is too expensive for USB High speed :-(.
>
> Agreed, we have seen many cases that have nothing to do with hardware
> design, but MUSB has to work in full-speed mode.
>
>>>
>>>> titled: CONFIG_USB_MUSB_NO_HIGHSPEED and then do:
>>>>
>>>> +#ifndef CONFIG_USB_MUSB_NO_HIGHSPEED | MUSB_POWER_HSENAB
>>>> +#endif
>>>>
>>> This would be good enough. The point is indeed to limit it to full
>>> speed.
>>>
>>>> Using CONFIG_USB_GADGET_DUALSPEED for this seems wrong, since
>>>> this has nothing to do with enabling dualspeed mode for the
>>>> gadget code really.
>>>
>>> I agree that the name is confusing.
>>
>> Yes, I vote for Hans suggestion.
>
> *Adding* a new macro CONFIG_USB_MUSB_NO_HIGHSPEED for musb driver causes
> CONFIG_USB_GADGET_DUALSPEED redundant, because both control for full-speed.
>
> I suggest to *rename* CONFIG_USB_GADGET_DUALSPEED to
> CONFIG_USB_FULLSPEED_ONLY. So that we can use one macro for both gadget
> and musb drivers. Considering supper-speed exists and future, I think
> CONFIG_USB_NO_HIGHSPEED is confusing...

If this is so, yes, of course, CONFIG_USB_GADGET_DUALSPEED
should be renamed only. A entry in README would be helpful here.

bye,
Heiko
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