ARM: 5967/1: at91_udc.c use spinlocks instead of local_irq_xxx
The locking code of this driver is reworked for preempt-rt.
For more info see:
http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20100203/09cdb3b4/attachment.el
http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20100203/3ad44e30/attachment.el
First applied: "at91_udc HW glitch"
http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=5966/1
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Harro Haan <hrhaan@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
index eaa79c8..fd6a757 100644
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -77,10 +77,10 @@
static const char ep0name[] = "ep0";
-#define at91_udp_read(dev, reg) \
- __raw_readl((dev)->udp_baseaddr + (reg))
-#define at91_udp_write(dev, reg, val) \
- __raw_writel((val), (dev)->udp_baseaddr + (reg))
+#define at91_udp_read(udc, reg) \
+ __raw_readl((udc)->udp_baseaddr + (reg))
+#define at91_udp_write(udc, reg, val) \
+ __raw_writel((val), (udc)->udp_baseaddr + (reg))
/*-------------------------------------------------------------------------*/
@@ -102,8 +102,9 @@
u32 csr;
struct at91_request *req;
unsigned long flags;
+ struct at91_udc *udc = ep->udc;
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
csr = __raw_readl(ep->creg);
@@ -147,7 +148,7 @@
&req->req, length,
req->req.length, req->req.buf);
}
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
}
static void proc_irq_show(struct seq_file *s, const char *label, u32 mask)
@@ -272,7 +273,9 @@
VDBG("%s done %p, status %d\n", ep->ep.name, req, status);
ep->stopped = 1;
+ spin_unlock(&udc->lock);
req->req.complete(&ep->ep, &req->req);
+ spin_lock(&udc->lock);
ep->stopped = stopped;
/* ep0 is always ready; other endpoints need a non-empty queue */
@@ -472,7 +475,7 @@
const struct usb_endpoint_descriptor *desc)
{
struct at91_ep *ep = container_of(_ep, struct at91_ep, ep);
- struct at91_udc *dev = ep->udc;
+ struct at91_udc *udc = ep->udc;
u16 maxpacket;
u32 tmp;
unsigned long flags;
@@ -487,7 +490,7 @@
return -EINVAL;
}
- if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
+ if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
DBG("bogus device state\n");
return -ESHUTDOWN;
}
@@ -521,7 +524,7 @@
}
ok:
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
/* initialize endpoint to match this descriptor */
ep->is_in = usb_endpoint_dir_in(desc);
@@ -540,10 +543,10 @@
* reset/init endpoint fifo. NOTE: leaves fifo_bank alone,
* since endpoint resets don't reset hw pingpong state.
*/
- at91_udp_write(dev, AT91_UDP_RST_EP, ep->int_mask);
- at91_udp_write(dev, AT91_UDP_RST_EP, 0);
+ at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
+ at91_udp_write(udc, AT91_UDP_RST_EP, 0);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return 0;
}
@@ -556,7 +559,7 @@
if (ep == &ep->udc->ep[0])
return -EINVAL;
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
nuke(ep, -ESHUTDOWN);
@@ -571,7 +574,7 @@
__raw_writel(0, ep->creg);
}
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return 0;
}
@@ -607,7 +610,7 @@
{
struct at91_request *req;
struct at91_ep *ep;
- struct at91_udc *dev;
+ struct at91_udc *udc;
int status;
unsigned long flags;
@@ -625,9 +628,9 @@
return -EINVAL;
}
- dev = ep->udc;
+ udc = ep->udc;
- if (!dev || !dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
+ if (!udc || !udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
DBG("invalid device\n");
return -EINVAL;
}
@@ -635,7 +638,7 @@
_req->status = -EINPROGRESS;
_req->actual = 0;
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
/* try to kickstart any empty and idle queue */
if (list_empty(&ep->queue) && !ep->stopped) {
@@ -653,7 +656,7 @@
if (is_ep0) {
u32 tmp;
- if (!dev->req_pending) {
+ if (!udc->req_pending) {
status = -EINVAL;
goto done;
}
@@ -662,11 +665,11 @@
* defer changing CONFG until after the gadget driver
* reconfigures the endpoints.
*/
- if (dev->wait_for_config_ack) {
- tmp = at91_udp_read(dev, AT91_UDP_GLB_STAT);
+ if (udc->wait_for_config_ack) {
+ tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
tmp ^= AT91_UDP_CONFG;
VDBG("toggle config\n");
- at91_udp_write(dev, AT91_UDP_GLB_STAT, tmp);
+ at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
}
if (req->req.length == 0) {
ep0_in_status:
@@ -676,7 +679,7 @@
tmp &= ~SET_FX;
tmp |= CLR_FX | AT91_UDP_TXPKTRDY;
__raw_writel(tmp, ep->creg);
- dev->req_pending = 0;
+ udc->req_pending = 0;
goto done;
}
}
@@ -695,31 +698,40 @@
if (req && !status) {
list_add_tail (&req->queue, &ep->queue);
- at91_udp_write(dev, AT91_UDP_IER, ep->int_mask);
+ at91_udp_write(udc, AT91_UDP_IER, ep->int_mask);
}
done:
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return (status < 0) ? status : 0;
}
static int at91_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
- struct at91_ep *ep;
+ struct at91_ep *ep;
struct at91_request *req;
+ unsigned long flags;
+ struct at91_udc *udc;
ep = container_of(_ep, struct at91_ep, ep);
if (!_ep || ep->ep.name == ep0name)
return -EINVAL;
+ udc = ep->udc;
+
+ spin_lock_irqsave(&udc->lock, flags);
+
/* make sure it's actually queued on this endpoint */
list_for_each_entry (req, &ep->queue, queue) {
if (&req->req == _req)
break;
}
- if (&req->req != _req)
+ if (&req->req != _req) {
+ spin_unlock_irqrestore(&udc->lock, flags);
return -EINVAL;
+ }
done(ep, req, -ECONNRESET);
+ spin_unlock_irqrestore(&udc->lock, flags);
return 0;
}
@@ -736,7 +748,7 @@
return -EINVAL;
creg = ep->creg;
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
csr = __raw_readl(creg);
@@ -761,7 +773,7 @@
__raw_writel(csr, creg);
}
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return status;
}
@@ -795,7 +807,7 @@
unsigned long flags;
DBG("%s\n", __func__ );
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
if (!udc->clocked || !udc->suspended)
goto done;
@@ -809,7 +821,7 @@
at91_udp_write(udc, AT91_UDP_GLB_STAT, glbstate);
done:
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return status;
}
@@ -851,8 +863,11 @@
ep->stopped = 1;
nuke(ep, -ESHUTDOWN);
}
- if (driver)
+ if (driver) {
+ spin_unlock(&udc->lock);
driver->disconnect(&udc->gadget);
+ spin_lock(&udc->lock);
+ }
udc_reinit(udc);
}
@@ -935,13 +950,13 @@
unsigned long flags;
// VDBG("vbus %s\n", is_active ? "on" : "off");
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
udc->vbus = (is_active != 0);
if (udc->driver)
pullup(udc, is_active);
else
pullup(udc, 0);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return 0;
}
@@ -950,10 +965,10 @@
struct at91_udc *udc = to_udc(gadget);
unsigned long flags;
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
udc->enabled = is_on = !!is_on;
pullup(udc, is_on);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return 0;
}
@@ -962,9 +977,9 @@
struct at91_udc *udc = to_udc(gadget);
unsigned long flags;
- local_irq_save(flags);
+ spin_lock_irqsave(&udc->lock, flags);
udc->selfpowered = (is_on != 0);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&udc->lock, flags);
return 0;
}
@@ -1226,8 +1241,11 @@
#undef w_length
/* pass request up to the gadget driver */
- if (udc->driver)
+ if (udc->driver) {
+ spin_unlock(&udc->lock);
status = udc->driver->setup(&udc->gadget, &pkt.r);
+ spin_lock(&udc->lock);
+ }
else
status = -ENODEV;
if (status < 0) {
@@ -1378,6 +1396,9 @@
struct at91_udc *udc = _udc;
u32 rescans = 5;
int disable_clock = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&udc->lock, flags);
if (!udc->clocked) {
clk_on(udc);
@@ -1433,8 +1454,11 @@
* and then into standby to avoid drawing more than
* 500uA power (2500uA for some high-power configs).
*/
- if (udc->driver && udc->driver->suspend)
+ if (udc->driver && udc->driver->suspend) {
+ spin_unlock(&udc->lock);
udc->driver->suspend(&udc->gadget);
+ spin_lock(&udc->lock);
+ }
/* host initiated resume */
} else if (status & AT91_UDP_RXRSM) {
@@ -1451,8 +1475,11 @@
* would normally want to switch out of slow clock
* mode into normal mode.
*/
- if (udc->driver && udc->driver->resume)
+ if (udc->driver && udc->driver->resume) {
+ spin_unlock(&udc->lock);
udc->driver->resume(&udc->gadget);
+ spin_lock(&udc->lock);
+ }
/* endpoint IRQs are cleared by handling them */
} else {
@@ -1474,6 +1501,8 @@
if (disable_clock)
clk_off(udc);
+ spin_unlock_irqrestore(&udc->lock, flags);
+
return IRQ_HANDLED;
}
@@ -1574,6 +1603,7 @@
{
struct at91_udc *udc = &controller;
int retval;
+ unsigned long flags;
if (!driver
|| driver->speed < USB_SPEED_FULL
@@ -1605,9 +1635,9 @@
return retval;
}
- local_irq_disable();
+ spin_lock_irqsave(&udc->lock, flags);
pullup(udc, 1);
- local_irq_enable();
+ spin_unlock_irqrestore(&udc->lock, flags);
DBG("bound to %s\n", driver->driver.name);
return 0;
@@ -1617,15 +1647,16 @@
int usb_gadget_unregister_driver (struct usb_gadget_driver *driver)
{
struct at91_udc *udc = &controller;
+ unsigned long flags;
if (!driver || driver != udc->driver || !driver->unbind)
return -EINVAL;
- local_irq_disable();
+ spin_lock_irqsave(&udc->lock, flags);
udc->enabled = 0;
at91_udp_write(udc, AT91_UDP_IDR, ~0);
pullup(udc, 0);
- local_irq_enable();
+ spin_unlock_irqrestore(&udc->lock, flags);
driver->unbind(&udc->gadget);
udc->gadget.dev.driver = NULL;
@@ -1641,8 +1672,13 @@
static void at91udc_shutdown(struct platform_device *dev)
{
+ struct at91_udc *udc = platform_get_drvdata(dev);
+ unsigned long flags;
+
/* force disconnect on reboot */
+ spin_lock_irqsave(&udc->lock, flags);
pullup(platform_get_drvdata(dev), 0);
+ spin_unlock_irqrestore(&udc->lock, flags);
}
static int __init at91udc_probe(struct platform_device *pdev)
@@ -1683,6 +1719,7 @@
udc->board = *(struct at91_udc_data *) dev->platform_data;
udc->pdev = pdev;
udc->enabled = 0;
+ spin_lock_init(&udc->lock);
/* rm9200 needs manual D+ pullup; off by default */
if (cpu_is_at91rm9200()) {
@@ -1804,13 +1841,16 @@
{
struct at91_udc *udc = platform_get_drvdata(pdev);
struct resource *res;
+ unsigned long flags;
DBG("remove\n");
if (udc->driver)
return -EBUSY;
+ spin_lock_irqsave(&udc->lock, flags);
pullup(udc, 0);
+ spin_unlock_irqrestore(&udc->lock, flags);
device_init_wakeup(&pdev->dev, 0);
remove_debug_file(udc);
@@ -1840,6 +1880,7 @@
{
struct at91_udc *udc = platform_get_drvdata(pdev);
int wake = udc->driver && device_may_wakeup(&pdev->dev);
+ unsigned long flags;
/* Unless we can act normally to the host (letting it wake us up
* whenever it has work for us) force disconnect. Wakeup requires
@@ -1849,8 +1890,10 @@
if ((!udc->suspended && udc->addr)
|| !wake
|| at91_suspend_entering_slow_clock()) {
+ spin_lock_irqsave(&udc->lock, flags);
pullup(udc, 0);
wake = 0;
+ spin_unlock_irqrestore(&udc->lock, flags);
} else
enable_irq_wake(udc->udp_irq);
@@ -1863,6 +1906,7 @@
static int at91udc_resume(struct platform_device *pdev)
{
struct at91_udc *udc = platform_get_drvdata(pdev);
+ unsigned long flags;
if (udc->board.vbus_pin > 0 && udc->active_suspend)
disable_irq_wake(udc->board.vbus_pin);
@@ -1870,8 +1914,11 @@
/* maybe reconnect to host; if so, clocks on */
if (udc->active_suspend)
disable_irq_wake(udc->udp_irq);
- else
+ else {
+ spin_lock_irqsave(&udc->lock, flags);
pullup(udc, 1);
+ spin_unlock_irqrestore(&udc->lock, flags);
+ }
return 0;
}
#else
diff --git a/drivers/usb/gadget/at91_udc.h b/drivers/usb/gadget/at91_udc.h
index c65d622..bc76a39 100644
--- a/drivers/usb/gadget/at91_udc.h
+++ b/drivers/usb/gadget/at91_udc.h
@@ -144,6 +144,7 @@
struct proc_dir_entry *pde;
void __iomem *udp_baseaddr;
int udp_irq;
+ spinlock_t lock;
};
static inline struct at91_udc *to_udc(struct usb_gadget *g)