On 4/8/2021 1:46 PM, Artur Petrosyan wrote:
> Fixes the implementation of exiting from partial power down
> power saving mode when PC is resumed.
>
> Added port connection status checking which prevents exiting from
> Partial Power Down mode from _dwc2_hcd_resume() if not in Partial
> Power Down mode.
>
> Rearranged the implementation to get rid of many "if"
> statements.
>
> NOTE: Switch case statement is used for hibernation partial
> power down and clock gating mode determination. In this patch
> only Partial Power Down is implemented the Hibernation and
> clock gating implementations are planned to be added.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Fixes: 6f6d70597c15 ("usb: dwc2: bus suspend/resume for hosts with DWC2_POWER_DOWN_PARAM_NONE")
> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@xxxxxxxxxxxx>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>
> ---
> Changes in v3:
> - None
> Changes in v2:
> - None
>
> drivers/usb/dwc2/hcd.c | 90 +++++++++++++++++++++---------------------
> 1 file changed, 46 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
> index 34030bafdff4..f096006df96f 100644
> --- a/drivers/usb/dwc2/hcd.c
> +++ b/drivers/usb/dwc2/hcd.c
> @@ -4427,7 +4427,7 @@ static int _dwc2_hcd_resume(struct usb_hcd *hcd)
> {
> struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd);
> unsigned long flags;
> - u32 pcgctl;
> + u32 hprt0;
> int ret = 0;
>
> spin_lock_irqsave(&hsotg->lock, flags);
> @@ -4438,11 +4438,40 @@ static int _dwc2_hcd_resume(struct usb_hcd *hcd)
> if (hsotg->lx_state != DWC2_L2)
> goto unlock;
>
> - if (hsotg->params.power_down > DWC2_POWER_DOWN_PARAM_PARTIAL) {
> + hprt0 = dwc2_read_hprt0(hsotg);
> +
> + /*
> + * Added port connection status checking which prevents exiting from
> + * Partial Power Down mode from _dwc2_hcd_resume() if not in Partial
> + * Power Down mode.
> + */
> + if (hprt0 & HPRT0_CONNSTS) {
> + hsotg->lx_state = DWC2_L0;
> + goto unlock;
> + }
> +
> + switch (hsotg->params.power_down) {
> + case DWC2_POWER_DOWN_PARAM_PARTIAL:
> + ret = dwc2_exit_partial_power_down(hsotg, 0, true);
> + if (ret)
> + dev_err(hsotg->dev,
> + "exit partial_power_down failed\n");
> + /*
> + * Set HW accessible bit before powering on the controller
> + * since an interrupt may rise.
> + */
> + set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> + break;
> + case DWC2_POWER_DOWN_PARAM_HIBERNATION:
> + case DWC2_POWER_DOWN_PARAM_NONE:
> + default:
> hsotg->lx_state = DWC2_L0;
> goto unlock;
> }
>
> + /* Change Root port status, as port status change occurred after resume.*/
> + hsotg->flags.b.port_suspend_change = 1;
> +
> /*
> * Enable power if not already done.
> * This must not be spinlocked since duration
> @@ -4454,52 +4483,25 @@ static int _dwc2_hcd_resume(struct usb_hcd *hcd)
> spin_lock_irqsave(&hsotg->lock, flags);
> }
>
> - if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_PARTIAL) {
> - /*
> - * Set HW accessible bit before powering on the controller
> - * since an interrupt may rise.
> - */
> - set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> -
> -
> - /* Exit partial_power_down */
> - ret = dwc2_exit_partial_power_down(hsotg, 0, true);
> - if (ret && (ret != -ENOTSUPP))
> - dev_err(hsotg->dev, "exit partial_power_down failed\n");
> - } else {
> - pcgctl = readl(hsotg->regs + PCGCTL);
> - pcgctl &= ~PCGCTL_STOPPCLK;
> - writel(pcgctl, hsotg->regs + PCGCTL);
> - }
> -
> - hsotg->lx_state = DWC2_L0;
> -
> + /* Enable external vbus supply after resuming the port. */
> spin_unlock_irqrestore(&hsotg->lock, flags);
> + dwc2_vbus_supply_init(hsotg);
>
> - if (hsotg->bus_suspended) {
> - spin_lock_irqsave(&hsotg->lock, flags);
> - hsotg->flags.b.port_suspend_change = 1;
> - spin_unlock_irqrestore(&hsotg->lock, flags);
> - dwc2_port_resume(hsotg);
> - } else {
> - if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_PARTIAL) {
> - dwc2_vbus_supply_init(hsotg);
> -
> - /* Wait for controller to correctly update D+/D- level */
> - usleep_range(3000, 5000);
> - }
> + /* Wait for controller to correctly update D+/D- level */
> + usleep_range(3000, 5000);
> + spin_lock_irqsave(&hsotg->lock, flags);
>
> - /*
> - * Clear Port Enable and Port Status changes.
> - * Enable Port Power.
> - */
> - dwc2_writel(hsotg, HPRT0_PWR | HPRT0_CONNDET |
> - HPRT0_ENACHG, HPRT0);
> - /* Wait for controller to detect Port Connect */
> - usleep_range(5000, 7000);
> - }
> + /*
> + * Clear Port Enable and Port Status changes.
> + * Enable Port Power.
> + */
> + dwc2_writel(hsotg, HPRT0_PWR | HPRT0_CONNDET |
> + HPRT0_ENACHG, HPRT0);
>
> - return ret;
> + /* Wait for controller to detect Port Connect */
> + spin_unlock_irqrestore(&hsotg->lock, flags);
> + usleep_range(5000, 7000);
> + spin_lock_irqsave(&hsotg->lock, flags);
> unlock:
> spin_unlock_irqrestore(&hsotg->lock, flags);
>
>
