[PATCH] usb: gadget: tegra-xudc: Fix idle suspend/resume

[PATCH] usb: gadget: tegra-xudc: Fix idle suspend/resume

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

When the XUDC device is idle (i.e. powergated), care must be taken not
to access any registers because that would lead to a crash.

Move the call to tegra_xudc_device_mode_off() into the same conditional
as the tegra_xudc_powergate() call to make sure we only force device
mode off if the XUDC is actually powered up.

Fixes: 49db427232fe ("usb: gadget: Add UDC driver for tegra XUSB device mode controller")
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/usb/gadget/udc/tegra-xudc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c
index 52a6add961f4..dfabc54cdc27 100644
--- a/drivers/usb/gadget/udc/tegra-xudc.c
+++ b/drivers/usb/gadget/udc/tegra-xudc.c
@@ -3840,11 +3840,11 @@ static int __maybe_unused tegra_xudc_suspend(struct device *dev)
 
 	flush_work(&xudc->usb_role_sw_work);
 
-	/* Forcibly disconnect before powergating. */
-	tegra_xudc_device_mode_off(xudc);
-
-	if (!pm_runtime_status_suspended(dev))
+	if (!pm_runtime_status_suspended(dev)) {
+		/* Forcibly disconnect before powergating. */
+		tegra_xudc_device_mode_off(xudc);
 		tegra_xudc_powergate(xudc);
+	}
 
 	pm_runtime_disable(dev);
 
-- 
2.24.1

Re: [PATCH] usb: gadget: tegra-xudc: Fix idle suspend/resume

[Jon Hunter]

On 17/04/2020 18:05, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> When the XUDC device is idle (i.e. powergated), care must be taken not
> to access any registers because that would lead to a crash.
> 
> Move the call to tegra_xudc_device_mode_off() into the same conditional
> as the tegra_xudc_powergate() call to make sure we only force device
> mode off if the XUDC is actually powered up.
> 
> Fixes: 49db427232fe ("usb: gadget: Add UDC driver for tegra XUSB device mode controller")
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/usb/gadget/udc/tegra-xudc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c
> index 52a6add961f4..dfabc54cdc27 100644
> --- a/drivers/usb/gadget/udc/tegra-xudc.c
> +++ b/drivers/usb/gadget/udc/tegra-xudc.c
> @@ -3840,11 +3840,11 @@ static int __maybe_unused tegra_xudc_suspend(struct device *dev)
>  
>  	flush_work(&xudc->usb_role_sw_work);
>  
> -	/* Forcibly disconnect before powergating. */
> -	tegra_xudc_device_mode_off(xudc);
> -
> -	if (!pm_runtime_status_suspended(dev))
> +	if (!pm_runtime_status_suspended(dev)) {
> +		/* Forcibly disconnect before powergating. */
> +		tegra_xudc_device_mode_off(xudc);
>  		tegra_xudc_powergate(xudc);
> +	}
>  
>  	pm_runtime_disable(dev);


Acked-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>

Cheers
Jon

-- 
nvpublic

Re: [PATCH] usb: gadget: tegra-xudc: Fix idle suspend/resume

[Thierry Reding]

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On Fri, Apr 17, 2020 at 07:05:37PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> When the XUDC device is idle (i.e. powergated), care must be taken not
> to access any registers because that would lead to a crash.
> 
> Move the call to tegra_xudc_device_mode_off() into the same conditional
> as the tegra_xudc_powergate() call to make sure we only force device
> mode off if the XUDC is actually powered up.
> 
> Fixes: 49db427232fe ("usb: gadget: Add UDC driver for tegra XUSB device mode controller")
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/usb/gadget/udc/tegra-xudc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

Hi Felipe, Greg,

can you guys pick this up for v5.7, please?

Thanks,
Thierry

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