Re: [RFT PATCH 1/2] usb: dwc2: Add a 10 ms delay to dwc2_core_reset()

[Doug Anderson]

Michael,

On Fri, Mar 4, 2016 at 4:09 PM, Michael Niewoehner <linux@xxxxxxxxxxxxxx> wrote:
>>> From testing and trying to make sense of the documentation, it appears
>>> that a 10 ms delay is needed after resetting the core to make sure that
>>> everything is stable and consistent.  Let's add it.
>>>
>>> In my testing (on rk3288) this allows us to revert commit
>>> 192cb07f7928 ("usb: dwc2: Fix probe problem on bcm2835").  Though I
>>> could never reproduce the problems on my board, this might also allow us
>>> to revert commit bd84f4ae9986 ("usb: dwc2: Add extra delay when forcing
>>> dr_mode").
>>>
>>> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
>>
>> Tested-by: Michael Niewoehner <linux@xxxxxxxxxxxxxx>

Thanks!  That's great news!


>> Iâm a bit confused since git log says bd84f4ae9986 has been merged in 62718e304aa6 but looking at drivers/usb/dwc2/core.c it seems the patch has not been applied anyways ...
>> However, I tested you your two patches with âmagically revertedâ bd84f4ae9986 (msleep 50) on rk3188.
>> The sdcard keeps being detected and boots just fine.
> I meant usb stick of courseâ too much sdcards in my head today \o/.

Odd.  It looks to be there for me...

$ git checkout 62718e304aa6
HEAD is now at 62718e304aa6... Merge tag 'usb-4.5-rc6' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

$ git grep -C3 "NOTE: This is required" -- drivers/usb/dwc2/core.c
drivers/usb/dwc2/core.c-        }
drivers/usb/dwc2/core.c-
drivers/usb/dwc2/core.c-        /*
drivers/usb/dwc2/core.c:         * NOTE: This is required for some
rockchip soc based
drivers/usb/dwc2/core.c-         * platforms.
drivers/usb/dwc2/core.c-         */
drivers/usb/dwc2/core.c-        msleep(50);