From: Darius Augulis <augulis.darius@xxxxxxxxx>
Workaround of hw bug in IMX UDC.
This bug causes wrong handling of CFG_CHG interrupt.
Workaround is documented inline source code.
Signed-off-by: Darius Augulis <augulis.darius@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/gadget/imx_udc.c | 158 +++++++++++++++++++++++++-----------------
drivers/usb/gadget/imx_udc.h | 1 +
2 files changed, 94 insertions(+), 65 deletions(-)
diff --git a/drivers/usb/gadget/imx_udc.c b/drivers/usb/gadget/imx_udc.c
index e590464..8d3c6a9 100644
--- a/drivers/usb/gadget/imx_udc.c
+++ b/drivers/usb/gadget/imx_udc.c
@@ -28,6 +28,7 @@
#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/timer.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
@@ -1013,70 +1014,32 @@ static void udc_stop_activity(struct imx_udc_struct *imx_usb,
*******************************************************************************
*/
-static irqreturn_t imx_udc_irq(int irq, void *dev)
+/*
+ * Called when timer expires.
+ * Timer is started when CFG_CHG is received.
+ */
+static void handle_config(unsigned long data)
{
- struct imx_udc_struct *imx_usb = dev;
+ struct imx_udc_struct *imx_usb = (void *)data;
struct usb_ctrlrequest u;
int temp, cfg, intf, alt;
- int intr = __raw_readl(imx_usb->base + USB_INTR);
-
- if (intr & (INTR_WAKEUP | INTR_SUSPEND | INTR_RESUME | INTR_RESET_START
- | INTR_RESET_STOP | INTR_CFG_CHG)) {
- dump_intr(__func__, intr, imx_usb->dev);
- dump_usb_stat(__func__, imx_usb);
- }
-
- if (!imx_usb->driver)
- goto end_irq;
-
- if (intr & INTR_WAKEUP) {
- if (imx_usb->gadget.speed == USB_SPEED_UNKNOWN
- && imx_usb->driver && imx_usb->driver->resume)
- imx_usb->driver->resume(&imx_usb->gadget);
- imx_usb->set_config = 0;
- imx_usb->gadget.speed = USB_SPEED_FULL;
- }
-
- if (intr & INTR_SUSPEND) {
- if (imx_usb->gadget.speed != USB_SPEED_UNKNOWN
- && imx_usb->driver && imx_usb->driver->suspend)
- imx_usb->driver->suspend(&imx_usb->gadget);
- imx_usb->set_config = 0;
- imx_usb->gadget.speed = USB_SPEED_UNKNOWN;
- }
- if (intr & INTR_RESET_START) {
- __raw_writel(intr, imx_usb->base + USB_INTR);
- udc_stop_activity(imx_usb, imx_usb->driver);
- imx_usb->set_config = 0;
- imx_usb->gadget.speed = USB_SPEED_UNKNOWN;
- }
-
- if (intr & INTR_RESET_STOP)
- imx_usb->gadget.speed = USB_SPEED_FULL;
+ local_irq_disable();
- if (intr & INTR_CFG_CHG) {
- __raw_writel(INTR_CFG_CHG, imx_usb->base + USB_INTR);
- temp = __raw_readl(imx_usb->base + USB_STAT);
- cfg = (temp & STAT_CFG) >> 5;
- intf = (temp & STAT_INTF) >> 3;
- alt = temp & STAT_ALTSET;
+ temp = __raw_readl(imx_usb->base + USB_STAT);
+ cfg = (temp & STAT_CFG) >> 5;
+ intf = (temp & STAT_INTF) >> 3;
+ alt = temp & STAT_ALTSET;
- D_REQ(imx_usb->dev,
- "<%s> orig config C=%d, I=%d, A=%d / "
- "req config C=%d, I=%d, A=%d\n",
- __func__, imx_usb->cfg, imx_usb->intf, imx_usb->alt,
- cfg, intf, alt);
+ D_REQ(imx_usb->dev,
+ "<%s> orig config C=%d, I=%d, A=%d / "
+ "req config C=%d, I=%d, A=%d\n",
+ __func__, imx_usb->cfg, imx_usb->intf, imx_usb->alt,
+ cfg, intf, alt);
- if (cfg != 1 && cfg != 2)
- goto end_irq;
+ if (cfg == 1 || cfg == 2) {
- imx_usb->set_config = 0;
-
- /* Config setup */
if (imx_usb->cfg != cfg) {
- D_REQ(imx_usb->dev,
- "<%s> Change config start\n", __func__);
u.bRequest = USB_REQ_SET_CONFIGURATION;
u.bRequestType = USB_DIR_OUT |
USB_TYPE_STANDARD |
@@ -1085,16 +1048,10 @@ static irqreturn_t imx_udc_irq(int irq, void *dev)
u.wIndex = 0;
u.wLength = 0;
imx_usb->cfg = cfg;
- imx_usb->set_config = 1;
imx_usb->driver->setup(&imx_usb->gadget, &u);
- imx_usb->set_config = 0;
- D_REQ(imx_usb->dev,
- "<%s> Change config done\n", __func__);
}
if (imx_usb->intf != intf || imx_usb->alt != alt) {
- D_REQ(imx_usb->dev,
- "<%s> Change interface start\n", __func__);
u.bRequest = USB_REQ_SET_INTERFACE;
u.bRequestType = USB_DIR_OUT |
USB_TYPE_STANDARD |
@@ -1104,14 +1061,30 @@ static irqreturn_t imx_udc_irq(int irq, void *dev)
u.wLength = 0;
imx_usb->intf = intf;
imx_usb->alt = alt;
- imx_usb->set_config = 1;
imx_usb->driver->setup(&imx_usb->gadget, &u);
- imx_usb->set_config = 0;
- D_REQ(imx_usb->dev,
- "<%s> Change interface done\n", __func__);
}
}
+ imx_usb->set_config = 0;
+
+ local_irq_enable();
+}
+
+static irqreturn_t imx_udc_irq(int irq, void *dev)
+{
+ struct imx_udc_struct *imx_usb = dev;
+ int intr = __raw_readl(imx_usb->base + USB_INTR);
+ int temp;
+
+ if (intr & (INTR_WAKEUP | INTR_SUSPEND | INTR_RESUME | INTR_RESET_START
+ | INTR_RESET_STOP | INTR_CFG_CHG)) {
+ dump_intr(__func__, intr, imx_usb->dev);
+ dump_usb_stat(__func__, imx_usb);
+ }
+
+ if (!imx_usb->driver)
+ goto end_irq;
+
if (intr & INTR_SOF) {
/* Copy from Freescale BSP.
We must enable SOF intr and set CMDOVER.
@@ -1125,6 +1098,55 @@ static irqreturn_t imx_udc_irq(int irq, void *dev)
}
}
+ if (intr & INTR_CFG_CHG) {
+ /* A workaround of serious IMX UDC bug.
+ Handling of CFG_CHG should be delayed for some time, because
+ IMX does not NACK the host when CFG_CHG interrupt is pending.
+ There is no time to handle current CFG_CHG
+ if next CFG_CHG or SETUP packed is send immediately.
+ We have to clear CFG_CHG, start the timer and
+ NACK the host by setting CTRL_CMDOVER
+ if it sends any SETUP packet.
+ When timer expires, handler is called to handle configuration
+ changes. While CFG_CHG is not handled (set_config=1),
+ we must NACK the host to every SETUP packed.
+ This delay prevents from going out of sync with host.
+ */
+ __raw_writel(INTR_CFG_CHG, imx_usb->base + USB_INTR);
+ imx_usb->set_config = 1;
+ mod_timer(&imx_usb->timer, jiffies + 5);
+ goto end_irq;
+ }
+
+ if (intr & INTR_WAKEUP) {
+ if (imx_usb->gadget.speed == USB_SPEED_UNKNOWN
+ && imx_usb->driver && imx_usb->driver->resume)
+ imx_usb->driver->resume(&imx_usb->gadget);
+ imx_usb->set_config = 0;
+ del_timer(&imx_usb->timer);
+ imx_usb->gadget.speed = USB_SPEED_FULL;
+ }
+
+ if (intr & INTR_SUSPEND) {
+ if (imx_usb->gadget.speed != USB_SPEED_UNKNOWN
+ && imx_usb->driver && imx_usb->driver->suspend)
+ imx_usb->driver->suspend(&imx_usb->gadget);
+ imx_usb->set_config = 0;
+ del_timer(&imx_usb->timer);
+ imx_usb->gadget.speed = USB_SPEED_UNKNOWN;
+ }
+
+ if (intr & INTR_RESET_START) {
+ __raw_writel(intr, imx_usb->base + USB_INTR);
+ udc_stop_activity(imx_usb, imx_usb->driver);
+ imx_usb->set_config = 0;
+ del_timer(&imx_usb->timer);
+ imx_usb->gadget.speed = USB_SPEED_UNKNOWN;
+ }
+
+ if (intr & INTR_RESET_STOP)
+ imx_usb->gadget.speed = USB_SPEED_FULL;
+
end_irq:
__raw_writel(intr, imx_usb->base + USB_INTR);
return IRQ_HANDLED;
@@ -1342,6 +1364,7 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
udc_stop_activity(imx_usb, driver);
imx_udc_disable(imx_usb);
+ del_timer(&imx_usb->timer);
driver->unbind(&imx_usb->gadget);
imx_usb->gadget.dev.driver = NULL;
@@ -1459,6 +1482,10 @@ static int __init imx_udc_probe(struct platform_device *pdev)
usb_init_data(imx_usb);
imx_udc_init(imx_usb);
+ init_timer(&imx_usb->timer);
+ imx_usb->timer.function = handle_config;
+ imx_usb->timer.data = (unsigned long)imx_usb;
+
return 0;
fail3:
@@ -1481,6 +1508,7 @@ static int __exit imx_udc_remove(struct platform_device *pdev)
int i;
imx_udc_disable(imx_usb);
+ del_timer(&imx_usb->timer);
for (i = 0; i < IMX_USB_NB_EP + 1; i++)
free_irq(imx_usb->usbd_int[i], imx_usb);
diff --git a/drivers/usb/gadget/imx_udc.h b/drivers/usb/gadget/imx_udc.h
index 6b0b1e3..b48ad59 100644
--- a/drivers/usb/gadget/imx_udc.h
+++ b/drivers/usb/gadget/imx_udc.h
@@ -59,6 +59,7 @@ struct imx_udc_struct {
struct device *dev;
struct imx_ep_struct imx_ep[IMX_USB_NB_EP];
struct clk *clk;
+ struct timer_list timer;
enum ep0_state ep0state;
struct resource *res;
void __iomem *base;
--
1.6.2
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