[U-Boot] About the way to fix platform specific issue in source file xhci.c (U-Boot)

[Ran Wang]

Hi Marek,
> -----Original Message-----
> From: Marek Vasut [mailto:marex at denx.de]
> Sent: Tuesday, October 31, 2017 6:24 PM
> To: Ran Wang <ran.wang_1 at nxp.com>; Marek Vasut
> <marek.vasut at gmail.com>
> Cc: open list <u-boot at lists.denx.de>; Bin Meng <bmeng.cn at gmail.com>
> Subject: Re: [U-Boot] About the way to fix platform specific issue in source
> file xhci.c (U-Boot)
> 
> On 10/31/2017 10:43 AM, Ran Wang wrote:
> > Hi
> >> -----Original Message-----
> >> From: Marek Vasut [mailto:marek.vasut at gmail.com]
> >> Sent: Tuesday, October 31, 2017 5:31 PM
> >> To: Ran Wang <ran.wang_1 at nxp.com>; Marek Vasut <marex at denx.de>
> >> Cc: open list <u-boot at lists.denx.de>
> >> Subject: Re: [U-Boot] About the way to fix platform specific issue in
> >> source file xhci.c (U-Boot)
> >>
> >> On 10/31/2017 10:15 AM, Ran Wang wrote:
> >>> Hi Marek,
> >>
> >> Hi!
> >>
> >>>> -----Original Message-----
> >>>> From: Marek Vasut [mailto:marex at denx.de]
> >>>> Sent: Monday, October 30, 2017 6:55 PM
> >>>> To: Ran Wang <ran.wang_1 at nxp.com>
> >>>> Cc: bmeng.cn at gmail.com
> >>>> Subject: Re: About the way to fix platform specific issue in source
> >>>> file xhci.c
> >>>> (U-Boot)
> >>>>
> >>>> On 10/30/2017 09:39 AM, Ran Wang wrote:
> >>>>> Hi Vasut,
> >>>>>    For git://git.denx.de/u-boot-usb.git, I work out a patch to fix
> >>>>> USB issue
> >>>> which will happen on SoC LS2080A only (it's using DWC3).
> >>>>>    Per my understanding, we should not use platform define in
> >>>>> xhci.c to
> >>>> control its effect. However, I am not sure how to do it that can be
> >>>> accepted by upstream, so send you this mail for suggestion before I
> >>>> post the patch to patchwork. Thank you in advance.
> >>>>
> >>>> This should be fixed in common code, not in drivers.
> >>>
> >>> Did you mean it should be fixed in common/usb*.c rather than
> >> drivers/usb/*?
> >>
> >> Yes
> >>
> >>> If yes, is it acceptable that I use 'if
> >>> defined(CONFIG_ARCH_LS2080A)' in
> >> common/usb.c?
> >>
> >> No
> >>
> >>> If answer is no, how should I do? I cannot find an example and not
> >>> sure it's OK to related rule.
> >>
> >> What is the problem exactly ?
> >> I recall there were reports of shitty USB sticks failing, but without
> >> further details, it's hard to tell if this is the same problem.
> >>
> > We observed some USB2.0 drives (Transcend 8GB, 4GB, Samtec) fail to be
> > enumerated by U-Boot, and if we try to add some time interval between
> > control transfers (not in bulk transfers), issue get resolved.
> 
> Try disabling cache support, does it still happen ?
> I had such an issue with DWC2 controller and it failed due to incorrect cache
> handling.
> 
Could you pls tell me where to disable it on DWC3? May sure I do the right change.

Best regards,
Ran