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>

1 files changed, 20 insertions, 14 deletions

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 7ac7b524243d..b50ec3714fd8 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -2247,25 +2247,31 @@ 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));
-                        hcchar &= ~HCCHAR_CHENA;
-                        hcchar |= HCCHAR_CHDIS;
-                        hcchar &= ~HCCHAR_EPDIR;
-                        dwc2_writel(hsotg, hcchar, 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));
-                        hcchar |= HCCHAR_CHENA | HCCHAR_CHDIS;
-                        hcchar &= ~HCCHAR_EPDIR;
-                        dwc2_writel(hsotg, hcchar, HCCHAR(i));
-                        dev_dbg(hsotg->dev, "%s: Halt channel %d\n",
-                                __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",
-                                         i);
+                        if (hcchar & HCCHAR_CHENA) {
+                                hcchar |= HCCHAR_CHENA | HCCHAR_CHDIS;
+                                hcchar &= ~HCCHAR_EPDIR;
+                                dwc2_writel(hsotg, hcchar, HCCHAR(i));
+                                dev_dbg(hsotg->dev, "%s: Halt channel %d\n",
+                                        __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",
+                                                 i);
+                                }
                         }
                 }
         }