Re: [PATCH 1/4] usb: dwc2: gadget: move gadget resume after the core is in L0 state

From: Minas Harutyunyan
Date: Wed Apr 22 2020 - 10:49:04 EST


Hi Fabrice,

On 4/21/2020 4:32 PM, Fabrice Gasnier wrote:
> When the remote wakeup interrupt is triggered, lx_state is resumed from L2
> to L0 state. But when the gadget resume is called, lx_state is still L2.
> This prevents the resume callback to queue any request. Any attempt
> to queue a request from resume callback will result in:
> - "submit request only in active state" debug message to be issued
> - dwc2_hsotg_ep_queue() returns -EAGAIN
>
> Move the call to resume gadget after the core is put in DWC2_L0 state.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
> ---
> drivers/usb/dwc2/core_intr.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
> index 876ff31..b8ebda5 100644
> --- a/drivers/usb/dwc2/core_intr.c
> +++ b/drivers/usb/dwc2/core_intr.c
> @@ -404,9 +404,11 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
> }
>
> if (dwc2_is_device_mode(hsotg)) {
> + enum dwc2_lx_state lx_state = hsotg->lx_state;
> +
> dev_dbg(hsotg->dev, "DSTS=0x%0x\n",
> dwc2_readl(hsotg, DSTS));
> - if (hsotg->lx_state == DWC2_L2) {
> + if (lx_state == DWC2_L2) {
> u32 dctl = dwc2_readl(hsotg, DCTL);
>
> /* Clear Remote Wakeup Signaling */
> @@ -415,11 +417,13 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
> ret = dwc2_exit_partial_power_down(hsotg, true);
> if (ret && (ret != -ENOTSUPP))
> dev_err(hsotg->dev, "exit power_down failed\n");
> -
> - call_gadget(hsotg, resume);
> }
> /* Change to L0 state */
> hsotg->lx_state = DWC2_L0;
> +
> + /* Gadget may queue new requests upon resume to L0 state */
> + if (lx_state == DWC2_L2)
> + call_gadget(hsotg, resume);
> } else {
> if (hsotg->params.power_down)
> return;
>

What about below patch without introducing additional variable.

diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index 876ff31261d5..543865e31c72 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -416,6 +416,8 @@ static void dwc2_handle_wakeup_detected_intr(struct
dwc2_hsotg *hsotg)
if (ret && (ret != -ENOTSUPP))
dev_err(hsotg->dev, "exit power_down
failed\n");

+ /* Change to L0 state */
+ hsotg->lx_state = DWC2_L0;
call_gadget(hsotg, resume);
}
/* Change to L0 state */


Thanks,
Minas