Re: [PATCH] usb: dwc2: Skip clock gating on Samsung SoCs

[Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>]

On 16/07/2021 11:07, Minas Harutyunyan wrote:
> Hi Krzysztof,
> 
> On 7/16/2021 12:10 PM, Krzysztof Kozlowski wrote:
>> On 16/07/2021 07:01, Marek Szyprowski wrote:
>>> Commit 0112b7ce68ea ("usb: dwc2: Update dwc2_handle_usb_suspend_intr
>>> function.") changed the way the driver handles power down modes in a such
>>> way that it uses clock gating when no other power down mode is available.
>>>
>>> This however doesn't work well on the DWC2 implementation used on the
>>> Samsung SoCs. When a clock gating is enabled, system hangs. It looks that
>>> the proper clock gating requires some additional glue code in the shared
>>> USB2 PHY and/or Samsung glue code for the DWC2. To restore driver
>>> operation on the Samsung SoCs simply skip enabling clock gating mode
>>> until one finds what is really needed to make it working reliably.
>>>
>>> Fixes: 0112b7ce68ea ("usb: dwc2: Update dwc2_handle_usb_suspend_intr function.")
>>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
>>> ---
>>>   drivers/usb/dwc2/core.h      | 4 ++++
>>>   drivers/usb/dwc2/core_intr.c | 3 ++-
>>>   drivers/usb/dwc2/hcd.c       | 6 ++++--
>>>   drivers/usb/dwc2/params.c    | 1 +
>>>   4 files changed, 11 insertions(+), 3 deletions(-)
>>>
>>
>>
>> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
>>
> What mean your "Acked-by" tag? Do you want to mention that this commit 
> "Tested-by" or "Reviewed-by" by you?

My "Acked-by" means exactly what Linux process defines:
https://elixir.bootlin.com/linux/latest/source/Documentation/process/submitting-patches.rst#L426

Acked-by is neither Tested-by nor Reviewed-by. For the definition
of these other tags, please also see link above.

Best regards,
Krzysztof