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

From: Andrew Halaney <ahalaney@redhat.com>
To: Johan Hovold <johan+linaro@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Felipe Balbi <balbi@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
	Konrad Dybcio <konrad.dybcio@somainline.org>,
	Krishna Kurapati <quic_kriskura@quicinc.com>,
	Stephen Boyd <swboyd@chromium.org>,
	Doug Anderson <dianders@chromium.org>,
	Matthias Kaehlcke <mka@chromium.org>,
	Pavankumar Kondeti <quic_pkondeti@quicinc.com>,
	quic_ppratap@quicinc.com, quic_vpulyala@quicinc.com,
	linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH 1/8] usb: dwc3: fix PHY disable sequence
Date: Tue, 2 Aug 2022 16:21:54 -0500	[thread overview]
Message-ID: <20220802212154.jh65gds4jpzbvqn6@halaneylaptop> (raw)
In-Reply-To: <20220802151404.1797-2-johan+linaro@kernel.org>

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@vger.kernel.org      # 4.8
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---

Reviewed-by: Andrew Halaney <ahalaney@redhat.com>

>  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
>