From b42e8090ba93526d6063108b25e5fc0f11f58770 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 20 May 2021 16:22:00 -0400 Subject: [PATCH] USB: UDC: Implement udc_async_callbacks in net2280 This patch adds a udc_async_callbacks handler to the net2280 UDC driver, which will prevent a theoretical race during gadget unbinding. The net2280 driver is sufficiently complicated that I didn't want to mess around with IRQ settings. Instead, the patch simply adds a new flag to control async callbacks, and checks the flag before issuing any of them. Acked-by: Felipe Balbi Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/20210520202200.GE1216852@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/udc/net2280.c | 49 ++++++++++++++++++++++++++-------------- drivers/usb/gadget/udc/net2280.h | 1 + 2 files changed, 33 insertions(+), 17 deletions(-) diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c index fc9f99f..0e0458e 100644 --- a/drivers/usb/gadget/udc/net2280.c +++ b/drivers/usb/gadget/udc/net2280.c @@ -1617,6 +1617,7 @@ static struct usb_ep *net2280_match_ep(struct usb_gadget *_gadget, static int net2280_start(struct usb_gadget *_gadget, struct usb_gadget_driver *driver); static int net2280_stop(struct usb_gadget *_gadget); +static void net2280_async_callbacks(struct usb_gadget *_gadget, bool enable); static const struct usb_gadget_ops net2280_ops = { .get_frame = net2280_get_frame, @@ -1625,6 +1626,7 @@ static const struct usb_gadget_ops net2280_ops = { .pullup = net2280_pullup, .udc_start = net2280_start, .udc_stop = net2280_stop, + .udc_async_callbacks = net2280_async_callbacks, .match_ep = net2280_match_ep, }; @@ -2472,7 +2474,7 @@ static void stop_activity(struct net2280 *dev, struct usb_gadget_driver *driver) nuke(&dev->ep[i]); /* report disconnect; the driver is already quiesced */ - if (driver) { + if (dev->async_callbacks && driver) { spin_unlock(&dev->lock); driver->disconnect(&dev->gadget); spin_lock(&dev->lock); @@ -2502,6 +2504,15 @@ static int net2280_stop(struct usb_gadget *_gadget) return 0; } +static void net2280_async_callbacks(struct usb_gadget *_gadget, bool enable) +{ + struct net2280 *dev = container_of(_gadget, struct net2280, gadget); + + spin_lock_irq(&dev->lock); + dev->async_callbacks = enable; + spin_unlock_irq(&dev->lock); +} + /*-------------------------------------------------------------------------*/ /* handle ep0, ep-e, ep-f with 64 byte packets: packet per irq. @@ -3042,9 +3053,11 @@ usb3_delegate: readl(&ep->cfg->ep_cfg)); ep->responded = 0; - spin_unlock(&dev->lock); - tmp = dev->driver->setup(&dev->gadget, &r); - spin_lock(&dev->lock); + if (dev->async_callbacks) { + spin_unlock(&dev->lock); + tmp = dev->driver->setup(&dev->gadget, &r); + spin_lock(&dev->lock); + } } do_stall3: if (tmp < 0) { @@ -3284,9 +3297,11 @@ delegate: w_value, w_index, w_length, readl(&ep->cfg->ep_cfg)); ep->responded = 0; - spin_unlock(&dev->lock); - tmp = dev->driver->setup(&dev->gadget, &u.r); - spin_lock(&dev->lock); + if (dev->async_callbacks) { + spin_unlock(&dev->lock); + tmp = dev->driver->setup(&dev->gadget, &u.r); + spin_lock(&dev->lock); + } } /* stall ep0 on error */ @@ -3391,14 +3406,14 @@ __acquires(dev->lock) if (disconnect || reset) { stop_activity(dev, dev->driver); ep0_start(dev); - spin_unlock(&dev->lock); - if (reset) - usb_gadget_udc_reset - (&dev->gadget, dev->driver); - else - (dev->driver->disconnect) - (&dev->gadget); - spin_lock(&dev->lock); + if (dev->async_callbacks) { + spin_unlock(&dev->lock); + if (reset) + usb_gadget_udc_reset(&dev->gadget, dev->driver); + else + (dev->driver->disconnect)(&dev->gadget); + spin_lock(&dev->lock); + } return; } } @@ -3419,12 +3434,12 @@ __acquires(dev->lock) writel(tmp, &dev->regs->irqstat1); spin_unlock(&dev->lock); if (stat & BIT(SUSPEND_REQUEST_INTERRUPT)) { - if (dev->driver->suspend) + if (dev->async_callbacks && dev->driver->suspend) dev->driver->suspend(&dev->gadget); if (!enable_suspend) stat &= ~BIT(SUSPEND_REQUEST_INTERRUPT); } else { - if (dev->driver->resume) + if (dev->async_callbacks && dev->driver->resume) dev->driver->resume(&dev->gadget); /* at high speed, note erratum 0133 */ } diff --git a/drivers/usb/gadget/udc/net2280.h b/drivers/usb/gadget/udc/net2280.h index 7da3dc1..34716a9 100644 --- a/drivers/usb/gadget/udc/net2280.h +++ b/drivers/usb/gadget/udc/net2280.h @@ -162,6 +162,7 @@ struct net2280 { ltm_enable:1, wakeup_enable:1, addressed_state:1, + async_callbacks:1, bug7734_patched:1; u16 chiprev; int enhanced_mode; -- 2.7.4