usb: dwc2: Fix channel disable flow

Channel disabling/halting should performed for enabled only channels
to avoid warnings "Unable to clear enable on channel N" which seen
if host works in Slave mode.
Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/hcd.c

@@ -2247,15 +2247,18 @@ static void dwc2_core_host_init(struct dwc2_hsotg *hsotg)
 		num_channels = hsotg->params.host_channels;
 		for (i = 0; i < num_channels; i++) {
 			hcchar = dwc2_readl(hsotg, HCCHAR(i));
+			if (hcchar & HCCHAR_CHENA) {
 				hcchar &= ~HCCHAR_CHENA;
 				hcchar |= HCCHAR_CHDIS;
 				hcchar &= ~HCCHAR_EPDIR;
 				dwc2_writel(hsotg, hcchar, HCCHAR(i));
 			}
+		}
 
 		/* Halt all channels to put them into a known state */
 		for (i = 0; i < num_channels; i++) {
 			hcchar = dwc2_readl(hsotg, HCCHAR(i));
+			if (hcchar & HCCHAR_CHENA) {
 				hcchar |= HCCHAR_CHENA | HCCHAR_CHDIS;
 				hcchar &= ~HCCHAR_EPDIR;
 				dwc2_writel(hsotg, hcchar, HCCHAR(i));
@@ -2263,12 +2266,15 @@ static void dwc2_core_host_init(struct dwc2_hsotg *hsotg)
 					__func__, i);
 
 				if (dwc2_hsotg_wait_bit_clear(hsotg, HCCHAR(i),
-						      HCCHAR_CHENA, 1000)) {
-				dev_warn(hsotg->dev, "Unable to clear enable on channel %d\n",
+							      HCCHAR_CHENA,
+							      1000)) {
+					dev_warn(hsotg->dev,
+						 "Unable to clear enable on channel %d\n",
 						 i);
 				}
 			}
 		}
+	}
 
 	/* Enable ACG feature in host mode, if supported */
 	dwc2_enable_acg(hsotg);