On 10/01/18 15:33, Felipe Balbi wrote:
>
> Hi,
>
> Roger Quadros <rogerq@xxxxxx> writes:
>> Felipe,
>>
>> On 10/01/18 15:11, Roger Quadros wrote:
>>> The USB PHYs should be requested only once during the life cycle of
>>> this driver.
>>>
>>> As dwc3_core_init() is called during system suspend/resume
>>> it will result in multiple calls to dwc3_core_get_phy() which is wrong.
>>>
>>> To prevent that let's move dwc3_core_get_phy() call
>>> outside dwc3_core_init().
>>>
>>> Fixes: 541768b08a4 ("usb: dwc3: core: Call dwc3_core_get_phy() before initializing phys")
>>> Cc: linux-stable <stable@xxxxxxxxxxxxxxx> # >= v4.13
>>> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
>>
>> FYI. this patch brings the code back to
>> revert 541768b08a40 ("usb: dwc3: core: Call dwc3_core_get_phy() before initializing phys")
>> revert f54edb539c11 ("usb: dwc3: core: initialize ULPI before trying to get the PHY")
>>
>> So looks like this will break ULPI PHY case?
>>
>> Where do we initialize ULPI PHY, in dwc3_phy_setup()?
>>
>> if so then 541768b08a40 breaks the ULPI PHY case as well, right?
>
> indeed, that commit regressed ULPI PHYs :-(
>
> Seems like it should be more like below:
>
> @@ -754,15 +754,15 @@ static int dwc3_core_init(struct dwc3 *dwc)
> dwc->maximum_speed = USB_SPEED_HIGH;
> }
>
> - ret = dwc3_core_get_phy(dwc);
> + ret = dwc3_phy_setup(dwc);
But can we do a dwc3_phy_setup() without doing the soft reset of the controller first?
> if (ret)
> goto err0;
>
> - ret = dwc3_core_soft_reset(dwc);
> + ret = dwc3_core_get_phy(dwc);
we can get_phy in dwc3_core_init() as it will get called on resume().
This was the $subject of this patch.
> if (ret)
> goto err0;
>
> - ret = dwc3_phy_setup(dwc);
> + ret = dwc3_core_soft_reset(dwc);
> if (ret)
> goto err0;
>
> And maybe we rename dwc3_phy_setup() to dwc3_phy_intf_config() just to
> make the name match what the function actually does. Can you check that
> it won't regress the case reported by Carlos? If that works, then we
> would have to move BOTH dwc3_phy_setup() (dwc3_phy_intf_config()) and
> dwc3_core_get_phy() outside of dwc3_core_init(), which would mean
> duplicated code in suspend/resume handlers.
>
> I'm sure we can sort that out in another way; but the proper order is:
>
> -> initialize ULPI (if necessary)
> -> get phy
> -> soft reset
>
--
cheers,
-roger
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