Re: [PATCH 1/1] usb: dwc2: disable power_down on Amlogic devices

[Minas Harutyunyan]

On 12/9/2018 11:01 PM, Martin Blumenstingl wrote:
> Disable power_down by setting the parameter to
> DWC2_POWER_DOWN_PARAM_NONE. This fixes a problem on various Amlogic
> Meson SoCs where USB devices are only recognized when plugged in before
> booting Linux. A hot-plugged USB device was not detected even though the
> device got power (my USB thumb drive for example has an LED which lit
> up).
> 
> A similar fix was implemented for Rockchip SoCs in commit c216765d3a1def
> ("usb: dwc2: disable power_down on rockchip devices"). That commit
> suggests that a change in the dwc2 driver is the cause because the
> default value for the "hibernate" parameter (which then got renamed to
> "power_down" to support other modes) was changed in the v4.17 merge
> window with:
> commit 6d23ee9caa6790 ("Merge tag 'usb-for-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-testing").
> 
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.19
> Suggested-by: Christian Hewitt <christianshewitt@xxxxxxxxx>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>

Acked-by: Minas Harutyunyan <hminas@xxxxxxxxxxxx>
> ---
>   drivers/usb/dwc2/params.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
> index 7c1b6938f212..38c813b1d203 100644
> --- a/drivers/usb/dwc2/params.c
> +++ b/drivers/usb/dwc2/params.c
> @@ -111,6 +111,7 @@ static void dwc2_set_amlogic_params(struct dwc2_hsotg *hsotg)
>   	p->phy_type = DWC2_PHY_TYPE_PARAM_UTMI;
>   	p->ahbcfg = GAHBCFG_HBSTLEN_INCR8 <<
>   		GAHBCFG_HBSTLEN_SHIFT;
> +	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;
>   }
>   
>   static void dwc2_set_amcc_params(struct dwc2_hsotg *hsotg)
>