From: Felipe Balbi <ba...@ti.com>
usb_gadget_set_state() will call sysfs_notify()
which might sleep. Some users might want to call
usb_gadget_set_state() from the very IRQ handler
which actually changes the gadget state.
Instead of having every UDC driver add their own
workqueue for such a simple notification, we're
adding it generically to our struct usb_gadget,
so the details are hidden from all UDC drivers.
Acked-by: Alan Stern <st...@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <ba...@ti.com>
(cherry picked from commit 5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15)
Conflicts:
drivers/usb/gadget/udc-core.c
<Conflicts with previous out of sequence commit 1894870 usb: gadget:
udc-core: fix the typo of udc state attribute>
Signed-off-by: Chang Rebecca Swee Fun <rebecca.swee.fun.ch...@intel.com>
---
drivers/usb/gadget/udc-core.c | 12 +++++++++++-
include/linux/usb/gadget.h | 4 ++++
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 13e25f8..3122ab9 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -23,6 +23,7 @@
#include <linux/list.h>
#include <linux/err.h>
#include <linux/dma-mapping.h>
+#include <linux/workqueue.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
@@ -105,11 +106,18 @@ EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
/* ------------------------------------------------------------------------- */
+static void usb_gadget_state_work(struct work_struct *work)
+{
+ struct usb_gadget *gadget = work_to_gadget(work);
+
+ sysfs_notify(&gadget->dev.kobj, NULL, "status");
+}
+
void usb_gadget_set_state(struct usb_gadget *gadget,
enum usb_device_state state)
{
gadget->state = state;
- sysfs_notify(&gadget->dev.kobj, NULL, "state");
+ schedule_work(&gadget->work);
}
EXPORT_SYMBOL_GPL(usb_gadget_set_state);
@@ -196,6 +204,7 @@ int usb_add_gadget_udc_release(struct device *parent,
struct usb_gadget *gadget,
goto err1;
dev_set_name(&gadget->dev, "gadget");
+ INIT_WORK(&gadget->work, usb_gadget_state_work);
gadget->dev.parent = parent;
#ifdef CONFIG_HAS_DMA
@@ -315,6 +324,7 @@ found:
usb_gadget_remove_driver(udc);
kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
+ flush_work(&gadget->work);
device_unregister(&udc->dev);
device_unregister(&gadget->dev);
}
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index f1b0dca..942ef5e 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -22,6 +22,7 @@
#include <linux/slab.h>
#include <linux/scatterlist.h>
#include <linux/types.h>
+#include <linux/workqueue.h>
#include <linux/usb/ch9.h>
struct usb_ep;
@@ -475,6 +476,7 @@ struct usb_gadget_ops {
/**
* struct usb_gadget - represents a usb slave device
+ * @work: (internal use) Workqueue to be used for sysfs_notify()
* @ops: Function pointers used to access hardware-specific operations.
* @ep0: Endpoint zero, used when reading or writing responses to
* driver setup() requests
@@ -520,6 +522,7 @@ struct usb_gadget_ops {
* device is acting as a B-Peripheral (so is_a_peripheral is false).
*/
struct usb_gadget {
+ struct work_struct work;
/* readonly to gadget driver */
const struct usb_gadget_ops *ops;
struct usb_ep *ep0;
@@ -538,6 +541,7 @@ struct usb_gadget {
unsigned out_epnum;
unsigned in_epnum;
};
+#define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
{ dev_set_drvdata(&gadget->dev, data); }
--
1.9.1
--
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