Hi Heiko,
On 4/10/2018 4:28 PM, Heiko Stuebner wrote:
> Am Montag, 26. März 2018, 11:00:01 CEST schrieb Tomeu Vizoso:
>> devm_regulator_get_optional returns -ENODEV if the regulator isn't
>> there, so if that's the case we have to make sure not to leave -ENODEV
>> in the regulator pointer.
>>
>> Also, make sure we return 0 in that case, but correctly propagate any
>> other errors. Also propagate the error from _dwc2_hcd_start.
>>
>> Fixes: 531ef5ebea96 ("usb: dwc2: add support for host mode external vbus supply")
>> Cc: Amelie Delaunay <amelie.delaunay@xxxxxx>
>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
>
> The patch that gets fixed here also breaks display-output on dwc2-based
> Rockchip devices (likely even more), probably due to making the regulator
> framework hickup.
>
Could you please elaborate what mean "breaks display-output".
On which Kernel version you apply this patch?
Thanks,
Minas
> With this patch applied, apart from not seeing the NULL-ptr, I also get
> display output on my rk3288-veycron Chromebook again, so
>
> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
>
>
>> v2: Only overwrite the error in the pointer after checking it (Heiko
>> Stübner <heiko@xxxxxxxxx>)
>> v3: Remove hunks that shouldn't be in this patch
>> v4: Don't overwrite the error code before returning it (kbuild test
>> robot <lkp@xxxxxxxxx>)
>> ---
>> drivers/usb/dwc2/hcd.c | 13 ++++++++-----
>> 1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
>> index 190f95964000..c51b73b3e048 100644
>> --- a/drivers/usb/dwc2/hcd.c
>> +++ b/drivers/usb/dwc2/hcd.c
>> @@ -358,9 +358,14 @@ static void dwc2_gusbcfg_init(struct dwc2_hsotg *hsotg)
>>
>> static int dwc2_vbus_supply_init(struct dwc2_hsotg *hsotg)
>> {
>> + int ret;
>> +
>> hsotg->vbus_supply = devm_regulator_get_optional(hsotg->dev, "vbus");
>> - if (IS_ERR(hsotg->vbus_supply))
>> - return 0;
>> + if (IS_ERR(hsotg->vbus_supply)) {
>> + ret = PTR_ERR(hsotg->vbus_supply);
>> + hsotg->vbus_supply = NULL;
>> + return ret == -ENODEV ? 0 : ret;
>> + }
>>
>> return regulator_enable(hsotg->vbus_supply);
>> }
>> @@ -4342,9 +4347,7 @@ static int _dwc2_hcd_start(struct usb_hcd *hcd)
>>
>> spin_unlock_irqrestore(&hsotg->lock, flags);
>>
>> - dwc2_vbus_supply_init(hsotg);
>> -
>> - return 0;
>> + return dwc2_vbus_supply_init(hsotg);
>> }
>>
>> /*
>>
>
>
>
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