Re: [PATCH v2 1/1] usb: dwc3: gadget: fix IRQ storm on invalid event buffer count

[Krishna Kurapati]

On 8/12/2026 1:51 PM, Jiazi Liu wrote:
> From: Jiazi Liu <jiazi.liu1984@xxxxxxxxx>

[...]

> ---
>   drivers/usb/dwc3/core.h   |  7 +++++++
>   drivers/usb/dwc3/gadget.c | 41 +++++++++++++++++++++++++++++++++++++--
>   2 files changed, 46 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 608daeb7ef10..b1cd888eca77 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -49,6 +49,7 @@
>   #define DWC3_ENDPOINTS_NUM	32
>   #define DWC3_XHCI_RESOURCES_NUM	2
>   #define DWC3_ISOC_MAX_RETRIES	5
> +#define DWC3_ERR_RECOVERY_MAX	3
>   
>   #define DWC3_SCRATCHBUF_SIZE	4096	/* each buffer is assumed to be 4KiB */
>   #define DWC3_EVENT_BUFFERS_SIZE	4096
> @@ -1004,6 +1005,7 @@ struct dwc3_glue_ops {
>   /**
>    * struct dwc3 - representation of our controller
>    * @drd_work: workqueue used for role swapping
> + * @err_recovery_work: workqueue used for controller error recovery
>    * @ep0_trb: trb which is used for the ctrl_req
>    * @bounce: address of bounce buffer
>    * @setup_buf: used while precessing STD USB requests
> @@ -1171,6 +1173,7 @@ struct dwc3_glue_ops {
>    * @wakeup_configured: set if the device is configured for remote wakeup.
>    * @suspended: set to track suspend event due to U3/L2.
>    * @susphy_state: state of DWC3_GUSB2PHYCFG_SUSPHY + DWC3_GUSB3PIPECTL_SUSPHY
> + * @err_dying: true when controller is in error recovery, reject all requests
>    *		  before PM suspend.

How about gadget_dying or gadget_died (similar to hc_died in xhci). The 
variable "err_dyring"is misleading.

>    * @imod_interval: set the interrupt moderation interval in 250ns
>    *			increments or 0 to disable.
> @@ -1186,9 +1189,11 @@ struct dwc3_glue_ops {
>    * @wakeup_pending_funcs: Indicates whether any interface has requested for
>    *			 function wakeup in bitmap format where bit position
>    *			 represents interface_id.
> + * @err_recovery_count: number of consecutive error recovery attempts
>    */
>   struct dwc3 {
>   	struct work_struct	drd_work;
> +	struct work_struct	err_recovery_work;
>   	struct dwc3_trb		*ep0_trb;
>   	void			*bounce;
>   	u8			*setup_buf;
> @@ -1420,6 +1425,7 @@ struct dwc3 {
>   	unsigned		wakeup_configured:1;
>   	unsigned		suspended:1;
>   	unsigned		susphy_state:1;
> +	unsigned		err_dying:1;
>   
>   	u16			imod_interval;
>   
> @@ -1429,6 +1435,7 @@ struct dwc3 {
>   	struct dentry		*debug_root;
>   	u32			gsbuscfg0_reqinfo;
>   	u32			wakeup_pending_funcs;
> +	u32			err_recovery_count;
>   };
>   
>   #define INCRX_BURST_MODE 0
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index fa0f16ffafef..05f3ffab6e47 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2054,6 +2054,9 @@ static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
>   
>   	int				ret;
>   
> +	if (dwc->err_dying)
> +		return -ESHUTDOWN;
> +

Not sure but should this check be added for all gadget_ops ?

Regards,
Krishna,