usb: dwc2: Change TxFIFO and RxFIFO flushing flow

Before flushing fifos required to check AHB master state and
lush when AHB master is in IDLE state.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index 6294cee..e85f2d2 100644 (file)
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -675,6 +675,11 @@ void dwc2_flush_tx_fifo(struct dwc2_hsotg *hsotg, const int num)
 
        dev_vdbg(hsotg->dev, "Flush Tx FIFO %d\n", num);
 
+       /* Wait for AHB master IDLE state */
+       if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 10000))
+               dev_warn(hsotg->dev, "%s:  HANG! AHB Idle GRSCTL\n",
+                        __func__);
+
        greset = GRSTCTL_TXFFLSH;
        greset |= num << GRSTCTL_TXFNUM_SHIFT & GRSTCTL_TXFNUM_MASK;
        dwc2_writel(greset, hsotg->regs + GRSTCTL);
@@ -698,6 +703,11 @@ void dwc2_flush_rx_fifo(struct dwc2_hsotg *hsotg)
 
        dev_vdbg(hsotg->dev, "%s()\n", __func__);
 
+       /* Wait for AHB master IDLE state */
+       if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 10000))
+               dev_warn(hsotg->dev, "%s:  HANG! AHB Idle GRSCTL\n",
+                        __func__);
+
        greset = GRSTCTL_RXFFLSH;
        dwc2_writel(greset, hsotg->regs + GRSTCTL);