USB: gadget: udc: Process disconnect synchronously

As the comment in usb_disconnect() hints, do not defer the
disconnect processing, and instead just do it directly in
the irq handler. This allows the driver to avoid using a
nowadays deprecated tasklet.

Acked-by: Felipe Balbi <[e-mail]>
Signed-off-by: Davidlohr Bueso <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/udc/snps_udc_core.c

···
 #include <asm/unaligned.h>
 #include "amd5536udc.h"
 
-static void udc_tasklet_disconnect(unsigned long);
 static void udc_setup_endpoints(struct udc *dev);
 static void udc_soft_reset(struct udc *dev);
 static struct udc_request *udc_alloc_bna_dummy(struct udc_ep *ep);
···
 static struct timer_list udc_pollstall_timer;
 static int stop_pollstall_timer;
 static DECLARE_COMPLETION(on_pollstall_exit);
-
-/* tasklet for usb disconnect */
-static DECLARE_TASKLET_OLD(disconnect_tasklet, udc_tasklet_disconnect);
 
 /* endpoint names used for print */
 static const char ep0_string[] = "ep0in";
···
  */
 static void usb_disconnect(struct udc *dev)
 {
+	u32 tmp;
+
 	/* Return if already disconnected */
 	if (!dev->connected)
 		return;
···
 	/* mask interrupts */
 	udc_mask_unused_interrupts(dev);
 
-	/* REVISIT there doesn't seem to be a point to having this
-	 * talk to a tasklet ... do it directly, we already hold
-	 * the spinlock needed to process the disconnect.
-	 */
-
-	tasklet_schedule(&disconnect_tasklet);
-}
-
-/* Tasklet for disconnect to be outside of interrupt context */
-static void udc_tasklet_disconnect(unsigned long par)
-{
-	struct udc *dev = udc;
-	u32 tmp;
-
-	DBG(dev, "Tasklet disconnect\n");
-	spin_lock_irq(&dev->lock);
-
 	if (dev->driver) {
 		spin_unlock(&dev->lock);
 		dev->driver->disconnect(&dev->gadget);
···
 		/* empty queues */
 		for (tmp = 0; tmp < UDC_EP_NUM; tmp++)
 			empty_req_queue(&dev->ep[tmp]);
-
 	}
 
 	/* disable ep0 */
-	ep_init(dev->regs,
-			&dev->ep[UDC_EP0IN_IX]);
-
+	ep_init(dev->regs, &dev->ep[UDC_EP0IN_IX]);
 
 	if (!soft_reset_occured) {
 		/* init controller by soft reset */
···
 		tmp = AMD_ADDBITS(tmp, UDC_DEVCFG_SPD_FS, UDC_DEVCFG_SPD);
 		writel(tmp, &dev->regs->cfg);
 	}
-
-	spin_unlock_irq(&dev->lock);
 }
 
 /* Reset the UDC core */