| Message ID | 20210416124827.9BB59A005D@mailhost.synopsys.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On 4/16/2021 4:48 PM, Artur Petrosyan wrote: > When dwc2 core is in hibernation mode loading > driver again causes driver fail. Because in > that mode registers are not accessible. > > In order to exit from hibernation checking > dwc2 core power saving state in "dwc2_driver_remove()" > function. If core is in hibernation, then checking the > operational mode of the driver. To check whether dwc2 core > is operating in host mode or device mode there is one way > which is retrieving the backup value of "gotgctl" and compare > the "CurMod" value. If previously core entered hibernation > in host mode then the exit is performed for host if not then > exit is performed for device mode. The introduced checking > is because in hibernation state all registers are not > accessible. > > Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> > Reported-by: kernel test robot <lkp@intel.com> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> > --- > drivers/usb/dwc2/platform.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c > index f8b819cfa80e..8ad33e042a14 100644 > --- a/drivers/usb/dwc2/platform.c > +++ b/drivers/usb/dwc2/platform.c > @@ -316,8 +316,23 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg) > static int dwc2_driver_remove(struct platform_device *dev) > { > struct dwc2_hsotg *hsotg = platform_get_drvdata(dev); > + struct dwc2_gregs_backup *gr; > int ret = 0; > > + gr = &hsotg->gr_backup; > + > + /* Exit Hibernation when driver is removed. */ > + if (hsotg->hibernated) { > + if (gr->gotgctl & GOTGCTL_CURMODE_HOST) > + ret = dwc2_exit_hibernation(hsotg, 0, 0, 1); > + else > + ret = dwc2_exit_hibernation(hsotg, 0, 0, 0); > + > + if (ret) > + dev_err(hsotg->dev, > + "exit hibernation failed.\n"); > + } > + > /* Exit Partial Power Down when driver is removed. */ > if (hsotg->in_ppd) { > ret = dwc2_exit_partial_power_down(hsotg, 0, true); >
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c index f8b819cfa80e..8ad33e042a14 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -316,8 +316,23 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg) static int dwc2_driver_remove(struct platform_device *dev) { struct dwc2_hsotg *hsotg = platform_get_drvdata(dev); + struct dwc2_gregs_backup *gr; int ret = 0; + gr = &hsotg->gr_backup; + + /* Exit Hibernation when driver is removed. */ + if (hsotg->hibernated) { + if (gr->gotgctl & GOTGCTL_CURMODE_HOST) + ret = dwc2_exit_hibernation(hsotg, 0, 0, 1); + else + ret = dwc2_exit_hibernation(hsotg, 0, 0, 0); + + if (ret) + dev_err(hsotg->dev, + "exit hibernation failed.\n"); + } + /* Exit Partial Power Down when driver is removed. */ if (hsotg->in_ppd) { ret = dwc2_exit_partial_power_down(hsotg, 0, true);
When dwc2 core is in hibernation mode loading driver again causes driver fail. Because in that mode registers are not accessible. In order to exit from hibernation checking dwc2 core power saving state in "dwc2_driver_remove()" function. If core is in hibernation, then checking the operational mode of the driver. To check whether dwc2 core is operating in host mode or device mode there is one way which is retrieving the backup value of "gotgctl" and compare the "CurMod" value. If previously core entered hibernation in host mode then the exit is performed for host if not then exit is performed for device mode. The introduced checking is because in hibernation state all registers are not accessible. Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> --- drivers/usb/dwc2/platform.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)