Re: [PATCH 1/8] usb: dwc3: fix PHY disable sequence

[Andrew Halaney]

On Tue, Aug 02, 2022 at 05:13:57PM +0200, Johan Hovold wrote:
> Generic PHYs must be powered-off before they can be tore down.
> 
> Similarly, suspending legacy PHYs after having powered them off makes no
> sense.
> 
> Fix the dwc3_core_exit() (e.g. called during suspend) and open-coded
> dwc3_probe() error-path sequences that got this wrong.
> 
> Note that this makes dwc3_core_exit() match the dwc3_core_init() error
> path with respect to powering off the PHYs.
> 
> Fixes: 03c1fd622f72 ("usb: dwc3: core: add phy cleanup for probe error handling")
> Fixes: c499ff71ff2a ("usb: dwc3: core: re-factor init and exit paths")
> Cc: stable@xxxxxxxxxxxxxxx      # 4.8
> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
> ---

Reviewed-by: Andrew Halaney <ahalaney@xxxxxxxxxx>

>  drivers/usb/dwc3/core.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index c5c238ab3083..16d1f328775f 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -833,15 +833,16 @@ static void dwc3_core_exit(struct dwc3 *dwc)
>  {
>  	dwc3_event_buffers_cleanup(dwc);
>  
> +	usb_phy_set_suspend(dwc->usb2_phy, 1);
> +	usb_phy_set_suspend(dwc->usb3_phy, 1);
> +	phy_power_off(dwc->usb2_generic_phy);
> +	phy_power_off(dwc->usb3_generic_phy);
> +
>  	usb_phy_shutdown(dwc->usb2_phy);
>  	usb_phy_shutdown(dwc->usb3_phy);
>  	phy_exit(dwc->usb2_generic_phy);
>  	phy_exit(dwc->usb3_generic_phy);
>  
> -	usb_phy_set_suspend(dwc->usb2_phy, 1);
> -	usb_phy_set_suspend(dwc->usb3_phy, 1);
> -	phy_power_off(dwc->usb2_generic_phy);
> -	phy_power_off(dwc->usb3_generic_phy);
>  	dwc3_clk_disable(dwc);
>  	reset_control_assert(dwc->reset);
>  }
> @@ -1879,16 +1880,16 @@ static int dwc3_probe(struct platform_device *pdev)
>  	dwc3_debugfs_exit(dwc);
>  	dwc3_event_buffers_cleanup(dwc);
>  
> -	usb_phy_shutdown(dwc->usb2_phy);
> -	usb_phy_shutdown(dwc->usb3_phy);
> -	phy_exit(dwc->usb2_generic_phy);
> -	phy_exit(dwc->usb3_generic_phy);
> -
>  	usb_phy_set_suspend(dwc->usb2_phy, 1);
>  	usb_phy_set_suspend(dwc->usb3_phy, 1);
>  	phy_power_off(dwc->usb2_generic_phy);
>  	phy_power_off(dwc->usb3_generic_phy);
>  
> +	usb_phy_shutdown(dwc->usb2_phy);
> +	usb_phy_shutdown(dwc->usb3_phy);
> +	phy_exit(dwc->usb2_generic_phy);
> +	phy_exit(dwc->usb3_generic_phy);
> +
>  	dwc3_ulpi_exit(dwc);
>  
>  err4:
> -- 
> 2.35.1
>