[U-Boot] [PATCH v1 0/2] usb: dfu: am335x: allow dfu in fullspeed mode only

[Lukasz Majewski <l.majewski@samsung.com>]

Hi Bin,

> Lukasz,
> 
> On 09/09/2014 08:43 AM, Lukasz Majewski wrote:
> > Hi Heiko,
> >
> >> This patchserie adds the new config option CONFIG_DFU_FULLSPEED.
> >
> > Is there any special reason to support Full Speed (12 Mbit/sec - USB
> > 1.1) and not rely solely on the High Speed (USB 2.0) as we do now?
> >
> 
> The drivers must support full-speed anyway based on the USB2.0 Specs.
> 
> I have seen many cases in which only full-speed is suitable due to 
> either board design or specific USB use case.
> 
> One example is that to better fit to the production firmware flashing 
> automation, a board does not use standard USB receptacle or plug, but
> a four touch pads on the PCB, so that the robot can grab the board
> and touch the pads to download the firmware. In this case signal
> integrity is a concern, but not download speed.

Thanks for example. 

Best regards,
Lukasz

> 
> Regards,
> -Bin.
> 
> >> If this is enabled DFU uses fullspeed only. This is used on the
> >> siemens boards.
> >
> > Is there any DFU problem with the mentioned Siemens board, that we
> > must use USB 1.1?
> >
> > I'd also appreciate more verbose rationale for this patch series -
> > why this change is needed? What is the expected improvement?
> >
> > Thanks in advance.
> >
> >>
> >> Cc: Tom Rini <trini@ti.com>
> >> Cc: Lukasz Majewski <l.majewski@samsung.com>
> >> Cc: Marek Vasut <marex@denx.de>
> >> Cc: Liu Bin <b-liu@ti.com>
> >> Cc: Lukas Stockmann <lukas.stockmann@siemens.com>
> >>
> >> Heiko Schocher (2):
> >>    usb: dfu: add config option to use in dfu mode fullspeed only
> >>    arm: am335x: siemens board use in DFU mode fullspeed only
> >>
> >>   README                                 | 3 +++
> >>   drivers/usb/gadget/f_dfu.c             | 3 +++
> >>   drivers/usb/gadget/g_dnl.c             | 3 +++
> >>   include/configs/siemens-am33x-common.h | 3 ++-
> >>   4 files changed, 11 insertions(+), 1 deletion(-)
> >>
> >
> >
> >
> 



-- 
Best regards,

Lukasz Majewski

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