This patch (as1598) adds support for the new "reset" callback to the
g_file_storage driver. Resets are handled slightly differently from
disconnects, in that the driver doesn't sync the backing storage file
during a reset but does during a disconnect.
The problem is that a file sync can take a long time if there are many
dirty pages, which can cause the driver's main thread to miss other
USB events if they arrive too quickly. After a disconnect we
generally don't expect to see other events in the near future, whereas
after a reset we do.
Unfortunately the driver already contains an FSG_STATE_RESET symbol.
The patch renames it to FSG_STATE_CLASS_RESET, because it refers to a
class-specific reset event rather than a general USB port reset, and
uses FSG_STATE_RESET for port resets. The g_mass_storage driver
shares a source file with g_file_storage; therefore it had to be
modified accordingly.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Chen Peter-B29397 <B29397@xxxxxxxxxxxxx>
---
drivers/usb/gadget/f_mass_storage.c | 5 +++--
drivers/usb/gadget/file_storage.c | 20 ++++++++++++++++----
drivers/usb/gadget/storage_common.c | 3 ++-
3 files changed, 21 insertions(+), 7 deletions(-)
Index: usb-3.5/drivers/usb/gadget/storage_common.c
===================================================================
--- usb-3.5.orig/drivers/usb/gadget/storage_common.c
+++ usb-3.5/drivers/usb/gadget/storage_common.c
@@ -279,9 +279,10 @@ enum fsg_state {
FSG_STATE_IDLE = 0,
FSG_STATE_ABORT_BULK_OUT,
- FSG_STATE_RESET,
+ FSG_STATE_CLASS_RESET,
FSG_STATE_INTERFACE_CHANGE,
FSG_STATE_CONFIG_CHANGE,
+ FSG_STATE_RESET,
FSG_STATE_DISCONNECT,
FSG_STATE_EXIT,
FSG_STATE_TERMINATED
Index: usb-3.5/drivers/usb/gadget/file_storage.c
===================================================================
--- usb-3.5.orig/drivers/usb/gadget/file_storage.c
+++ usb-3.5/drivers/usb/gadget/file_storage.c
@@ -676,10 +676,18 @@ static void fsg_disconnect(struct usb_ga
{
struct fsg_dev *fsg = get_gadget_data(gadget);
- DBG(fsg, "disconnect or port reset\n");
+ DBG(fsg, "disconnect\n");
raise_exception(fsg, FSG_STATE_DISCONNECT);
}
+static void fsg_reset(struct usb_gadget *gadget)
+{
+ struct fsg_dev *fsg = get_gadget_data(gadget);
+
+ DBG(fsg, "port reset\n");
+ raise_exception(fsg, FSG_STATE_RESET);
+}
+
static int ep0_queue(struct fsg_dev *fsg)
{
@@ -816,7 +824,7 @@ static void received_cbi_adsc(struct fsg
/* Raise an exception to stop the current operation
* and reinitialize our state. */
DBG(fsg, "cbi reset request\n");
- raise_exception(fsg, FSG_STATE_RESET);
+ raise_exception(fsg, FSG_STATE_CLASS_RESET);
return;
}
@@ -867,7 +875,7 @@ static int class_setup_req(struct fsg_de
/* Raise an exception to stop the current operation
* and reinitialize our state. */
DBG(fsg, "bulk reset request\n");
- raise_exception(fsg, FSG_STATE_RESET);
+ raise_exception(fsg, FSG_STATE_CLASS_RESET);
value = DELAYED_STATUS;
break;
@@ -3006,7 +3014,7 @@ static void handle_exception(struct fsg_
spin_unlock_irq(&fsg->lock);
break;
- case FSG_STATE_RESET:
+ case FSG_STATE_CLASS_RESET:
/* In case we were forced against our will to halt a
* bulk endpoint, clear the halt now. (The SuperH UDC
* requires this.) */
@@ -3050,6 +3058,9 @@ static void handle_exception(struct fsg_
case FSG_STATE_DISCONNECT:
for (i = 0; i < fsg->nluns; ++i)
fsg_lun_fsync_sub(fsg->luns + i);
+ /* FALL THROUGH */
+
+ case FSG_STATE_RESET:
do_set_config(fsg, 0); // Unconfigured state
break;
@@ -3608,6 +3619,7 @@ static struct usb_gadget_driver fsg_dri
.function = (char *) fsg_string_product,
.unbind = fsg_unbind,
.disconnect = fsg_disconnect,
+ .reset = fsg_reset,
.setup = fsg_setup,
.suspend = fsg_suspend,
.resume = fsg_resume,
Index: usb-3.5/drivers/usb/gadget/f_mass_storage.c
===================================================================
--- usb-3.5.orig/drivers/usb/gadget/f_mass_storage.c
+++ usb-3.5/drivers/usb/gadget/f_mass_storage.c
@@ -554,7 +554,7 @@ static int fsg_setup(struct usb_function
* and reinitialize our state.
*/
DBG(fsg, "bulk reset request\n");
- raise_exception(fsg->common, FSG_STATE_RESET);
+ raise_exception(fsg->common, FSG_STATE_CLASS_RESET);
return DELAYED_STATUS;
case US_BULK_GET_MAX_LUN:
@@ -2470,7 +2470,7 @@ static void handle_exception(struct fsg_
spin_unlock_irq(&common->lock);
break;
- case FSG_STATE_RESET:
+ case FSG_STATE_CLASS_RESET:
/*
* In case we were forced against our will to halt a
* bulk endpoint, clear the halt now. (The SuperH UDC
@@ -2511,6 +2511,7 @@ static void handle_exception(struct fsg_
case FSG_STATE_INTERFACE_CHANGE:
case FSG_STATE_DISCONNECT:
+ case FSG_STATE_RESET:
case FSG_STATE_COMMAND_PHASE:
case FSG_STATE_DATA_PHASE:
case FSG_STATE_STATUS_PHASE:
--
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