[U-Boot] [PATCH v2] sunxi: A64: OHCI: prevent turning off shared USB clock

[Andre Przywara]

Hi,

On 05/07/18 10:25, Marek Vasut wrote:
> On 07/05/2018 01:57 AM, Andre Przywara wrote:
>> On the A64 the clock for the first USB controller is actually the parent
>> of the clock for the second controller, so turning them off in that order
>> makes the system hang.
>> Fix this by only turning off *both* clocks when the *last* OHCI controller
>> is brought down. This covers the case when only one controller is used.
>>
>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>> ---
>> Hi,
>>
>> as requested by Marek, a second version to address the problem of only
>> one controller instantiated. I tested all cases:
>> - only [EO]HCI1 enabled (current U-Boot master DT)
>> - both controllers enabled (mainline Linux DT)
>> - only [EO]HCI0 enabled (DT hack)
>> In all cases the system booted without hanging, plus I confirmed that
>> the USB clocks were disabled in all cases (early in the kernel).
>>
>> Cheers,
>> Andre.
>>
>> P.S. I found the MMC0, EMAC and USB-OTG AHB gates and resets still running,
>> but this is an unrelated issue and no regression. Just in case somebody
>> feels bored ...
> 
> Applied, thanks for all the effort you put into this .

Thank _you_ for staying on this, and insisting on the more robust solution!

Cheers,
Andre.