usb: dwc3: apple: Do not use host-vbus-glitches workaround

It results in SErrors during init presumedly because MMIO accesses fail
while certain parts are shutdown.

Fixes: a6ba1e4 ("usb: dwc3: apply snps,host-vbus-glitches workaround unconditionally")
Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

drivers/usb/dwc3/core.c

@@ -2265,6 +2265,7 @@ static int dwc3_probe(struct platform_device *pdev)
 
 			dwc->dr_mode = USB_DR_MODE_OTG;
 			dwc->role_switch_reset_quirk = true;
+			dwc->no_early_roothub_poweroff = true;
 		}
 	}
 

drivers/usb/dwc3/core.h

@@ -1154,6 +1154,7 @@ struct dwc3_scratchpad_array {
  * @susphy_state: state of DWC3_GUSB2PHYCFG_SUSPHY + DWC3_GUSB3PIPECTL_SUSPHY
  *		  before PM suspend.
  * @role_switch_reset_quirk: set to force reinitialization after any role switch
+ * @no_early_roothub_poweroff: set to skip early root hub port power off
  * @imod_interval: set the interrupt moderation interval in 250ns
  *			increments or 0 to disable.
  * @max_cfg_eps: current max number of IN eps used across all USB configs.
@@ -1392,6 +1393,7 @@ struct dwc3 {
 	unsigned		susphy_state:1;
 
 	unsigned		role_switch_reset_quirk:1;
+	unsigned		no_early_roothub_poweroff:1;
 
 	u16			imod_interval;
 

drivers/usb/dwc3/host.c

@@ -134,8 +134,11 @@ int dwc3_host_init(struct dwc3 *dwc)
 	/*
 	 * Some platforms need to power off all Root hub ports immediately after DWC3 set to host
 	 * mode to avoid VBUS glitch happen when xhci get reset later.
+	 * On Apple platforms we must not touch any MMIO yet because dwc3
+	 * will not work correctly before its PHY has been initialized.
 	 */
-	dwc3_power_off_all_roothub_ports(dwc);
+	if (!dwc->no_early_roothub_poweroff)
+		dwc3_power_off_all_roothub_ports(dwc);
 
 	irq = dwc3_host_get_irq(dwc);
 	if (irq < 0)