[PATCH 5.6 165/194] usb: gadget: tegra-xudc: Fix idle suspend/resume

Greg Kroah-Hartman
2020-05-18T18:07:57Z

From: Thierry Reding <treding@nvidia.com>

commit 0534d40160cb9505073b0ecf5e7210daee319a66 upstream.

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")
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/gadget/udc/tegra-xudc.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/usb/gadget/udc/tegra-xudc.c
+++ b/drivers/usb/gadget/udc/tegra-xudc.c
@@ -3740,11 +3740,11 @@ static int __maybe_unused tegra_xudc_sus

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);