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Commit b6b4a7e5 authored by Sriharsha Allenki's avatar Sriharsha Allenki Committed by Jack Pham
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usb: dwc3: Prevent continuous retries on error event 



Upon USB core generating an erratic error event, the
dwc3-msm driver resets and restarts the core. Even
after this if core could not recover, the driver
keep on trying the same in a infinite loop. This could
lead to the hogging of system resources leading to
system failure. Prevent this by trying a maximum of three
times to recover upon erratic error event.

An example of continuous generation of error events is
a DCP charger detected as SDP by the PMIC and core entering
device mode. In this case, the core could not recover
even after several tries.

Change-Id: Ic2f2f10e6bcc7480be5116746072b0fb1651ce10
Signed-off-by: default avatarSriharsha Allenki <sallenki@codeaurora.org>
Signed-off-by: default avatarJack Pham <jackp@codeaurora.org>
parent c32fced5

drivers/usb/dwc3/core.h

+2 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#define DWC3_ENDPOINTS_NUM	32

#define DWC3_XHCI_RESOURCES_NUM	2

#define DWC3_ISOC_MAX_RETRIES	5

#define MAX_ERROR_RECOVERY_TRIES	3



#define DWC3_SCRATCHBUF_SIZE	4096	/* each buffer is assumed to be 4KiB */

#define DWC3_EVENT_BUFFERS_SIZE	4096
@@ -1352,6 +1353,7 @@ struct dwc3 { 
	 * connected devices on PM resume.

	 */

	bool			host_poweroff_in_pm_suspend;

	int			retries_on_error;

};



#define INCRX_BURST_MODE 0

drivers/usb/dwc3/gadget.c

+7 −1
Original line number Diff line number Diff line
@@ -2012,6 +2012,8 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend) 
		dwc->pullups_connected = true;

	} else {

		dwc3_gadget_disable_irq(dwc);



		dwc->err_evt_seen = false;

		dwc->pullups_connected = false;

		__dwc3_gadget_ep_disable(dwc->eps[0]);

		__dwc3_gadget_ep_disable(dwc->eps[1]);
@@ -3192,6 +3194,9 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc) 
		dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);

	}



	/* Reset the retry on erratic error event count */

	dwc->retries_on_error = 0;



	/*

	 * RAMClkSel is reset to 0 after USB reset, so it must be reprogrammed

	 * each time on Connect Done.
@@ -3530,7 +3535,7 @@ static void dwc3_gadget_interrupt(struct dwc3 *dwc, 
		dwc->dbg_gadget_events.sof++;

		break;

	case DWC3_DEVICE_EVENT_ERRATIC_ERROR:

		dbg_event(0xFF, "ERROR", 0);

		dbg_event(0xFF, "ERROR", dwc->retries_on_error);

		dwc->dbg_gadget_events.erratic_error++;

		dwc->err_evt_seen = true;

		break;
@@ -3588,6 +3593,7 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt) 
			if (dwc3_notify_event(dwc,

						DWC3_CONTROLLER_ERROR_EVENT, 0))

				dwc->err_evt_seen = 0;

			dwc->retries_on_error++;

			break;

		}