[PATCH] USB Gadget: file_storage: remove "volatile" declarations
This patch (as612) removes the "volatile" declarations from the file-storage gadget. It turns out that they aren't needed for anything much; adding a few memory barriers does a sufficient job. The patch also removes a wait_queue. Not much point having a queue when only one task is ever going to be on it! Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern
Greg Kroah-Hartman
parent
bd39b7f195
commit
a21d4fed4b
|
|
@ -239,7 +239,6 @@
|
|||
#include <linux/string.h>
|
||||
#include <linux/suspend.h>
|
||||
#include <linux/utsname.h>
|
||||
#include <linux/wait.h>
|
||||
|
||||
#include <linux/usb_ch9.h>
|
||||
#include <linux/usb_gadget.h>
|
||||
|
|
@ -251,7 +250,7 @@
|
|||
|
||||
#define DRIVER_DESC "File-backed Storage Gadget"
|
||||
#define DRIVER_NAME "g_file_storage"
|
||||
#define DRIVER_VERSION "20 October 2004"
|
||||
#define DRIVER_VERSION "28 November 2005"
|
||||
|
||||
static const char longname[] = DRIVER_DESC;
|
||||
static const char shortname[] = DRIVER_NAME;
|
||||
|
|
@ -588,7 +587,7 @@ enum fsg_buffer_state {
|
|||
struct fsg_buffhd {
|
||||
void *buf;
|
||||
dma_addr_t dma;
|
||||
volatile enum fsg_buffer_state state;
|
||||
enum fsg_buffer_state state;
|
||||
struct fsg_buffhd *next;
|
||||
|
||||
/* The NetChip 2280 is faster, and handles some protocol faults
|
||||
|
|
@ -597,9 +596,9 @@ struct fsg_buffhd {
|
|||
unsigned int bulk_out_intended_length;
|
||||
|
||||
struct usb_request *inreq;
|
||||
volatile int inreq_busy;
|
||||
int inreq_busy;
|
||||
struct usb_request *outreq;
|
||||
volatile int outreq_busy;
|
||||
int outreq_busy;
|
||||
};
|
||||
|
||||
enum fsg_state {
|
||||
|
|
@ -637,11 +636,11 @@ struct fsg_dev {
|
|||
|
||||
struct usb_ep *ep0; // Handy copy of gadget->ep0
|
||||
struct usb_request *ep0req; // For control responses
|
||||
volatile unsigned int ep0_req_tag;
|
||||
unsigned int ep0_req_tag;
|
||||
const char *ep0req_name;
|
||||
|
||||
struct usb_request *intreq; // For interrupt responses
|
||||
volatile int intreq_busy;
|
||||
int intreq_busy;
|
||||
struct fsg_buffhd *intr_buffhd;
|
||||
|
||||
unsigned int bulk_out_maxpacket;
|
||||
|
|
@ -671,7 +670,6 @@ struct fsg_dev {
|
|||
struct fsg_buffhd *next_buffhd_to_drain;
|
||||
struct fsg_buffhd buffhds[NUM_BUFFERS];
|
||||
|
||||
wait_queue_head_t thread_wqh;
|
||||
int thread_wakeup_needed;
|
||||
struct completion thread_notifier;
|
||||
struct task_struct *thread_task;
|
||||
|
|
@ -1076,11 +1074,13 @@ static int populate_config_buf(struct usb_gadget *gadget,
|
|||
|
||||
/* These routines may be called in process context or in_irq */
|
||||
|
||||
/* Caller must hold fsg->lock */
|
||||
static void wakeup_thread(struct fsg_dev *fsg)
|
||||
{
|
||||
/* Tell the main thread that something has happened */
|
||||
fsg->thread_wakeup_needed = 1;
|
||||
wake_up_all(&fsg->thread_wqh);
|
||||
if (fsg->thread_task)
|
||||
wake_up_process(fsg->thread_task);
|
||||
}
|
||||
|
||||
|
||||
|
|
@ -1167,11 +1167,12 @@ static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
|
|||
usb_ep_fifo_flush(ep);
|
||||
|
||||
/* Hold the lock while we update the request and buffer states */
|
||||
smp_wmb();
|
||||
spin_lock(&fsg->lock);
|
||||
bh->inreq_busy = 0;
|
||||
bh->state = BUF_STATE_EMPTY;
|
||||
spin_unlock(&fsg->lock);
|
||||
wakeup_thread(fsg);
|
||||
spin_unlock(&fsg->lock);
|
||||
}
|
||||
|
||||
static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
|
||||
|
|
@ -1188,11 +1189,12 @@ static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
|
|||
usb_ep_fifo_flush(ep);
|
||||
|
||||
/* Hold the lock while we update the request and buffer states */
|
||||
smp_wmb();
|
||||
spin_lock(&fsg->lock);
|
||||
bh->outreq_busy = 0;
|
||||
bh->state = BUF_STATE_FULL;
|
||||
spin_unlock(&fsg->lock);
|
||||
wakeup_thread(fsg);
|
||||
spin_unlock(&fsg->lock);
|
||||
}
|
||||
|
||||
|
||||
|
|
@ -1209,11 +1211,12 @@ static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
|
|||
usb_ep_fifo_flush(ep);
|
||||
|
||||
/* Hold the lock while we update the request and buffer states */
|
||||
smp_wmb();
|
||||
spin_lock(&fsg->lock);
|
||||
fsg->intreq_busy = 0;
|
||||
bh->state = BUF_STATE_EMPTY;
|
||||
spin_unlock(&fsg->lock);
|
||||
wakeup_thread(fsg);
|
||||
spin_unlock(&fsg->lock);
|
||||
}
|
||||
|
||||
#else
|
||||
|
|
@ -1264,8 +1267,8 @@ static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
|
|||
fsg->cbbuf_cmnd_size = req->actual;
|
||||
memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
|
||||
|
||||
spin_unlock(&fsg->lock);
|
||||
wakeup_thread(fsg);
|
||||
spin_unlock(&fsg->lock);
|
||||
}
|
||||
|
||||
#else
|
||||
|
|
@ -1517,8 +1520,8 @@ static int fsg_setup(struct usb_gadget *gadget,
|
|||
|
||||
/* Use this for bulk or interrupt transfers, not ep0 */
|
||||
static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
|
||||
struct usb_request *req, volatile int *pbusy,
|
||||
volatile enum fsg_buffer_state *state)
|
||||
struct usb_request *req, int *pbusy,
|
||||
enum fsg_buffer_state *state)
|
||||
{
|
||||
int rc;
|
||||
|
||||
|
|
@ -1526,8 +1529,11 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
|
|||
dump_msg(fsg, "bulk-in", req->buf, req->length);
|
||||
else if (ep == fsg->intr_in)
|
||||
dump_msg(fsg, "intr-in", req->buf, req->length);
|
||||
|
||||
spin_lock_irq(&fsg->lock);
|
||||
*pbusy = 1;
|
||||
*state = BUF_STATE_BUSY;
|
||||
spin_unlock_irq(&fsg->lock);
|
||||
rc = usb_ep_queue(ep, req, GFP_KERNEL);
|
||||
if (rc != 0) {
|
||||
*pbusy = 0;
|
||||
|
|
@ -1547,14 +1553,23 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
|
|||
|
||||
static int sleep_thread(struct fsg_dev *fsg)
|
||||
{
|
||||
int rc;
|
||||
int rc = 0;
|
||||
|
||||
/* Wait until a signal arrives or we are woken up */
|
||||
rc = wait_event_interruptible(fsg->thread_wqh,
|
||||
fsg->thread_wakeup_needed);
|
||||
for (;;) {
|
||||
try_to_freeze();
|
||||
set_current_state(TASK_INTERRUPTIBLE);
|
||||
if (signal_pending(current)) {
|
||||
rc = -EINTR;
|
||||
break;
|
||||
}
|
||||
if (fsg->thread_wakeup_needed)
|
||||
break;
|
||||
schedule();
|
||||
}
|
||||
__set_current_state(TASK_RUNNING);
|
||||
fsg->thread_wakeup_needed = 0;
|
||||
try_to_freeze();
|
||||
return (rc ? -EINTR : 0);
|
||||
return rc;
|
||||
}
|
||||
|
||||
|
||||
|
|
@ -1791,6 +1806,7 @@ static int do_write(struct fsg_dev *fsg)
|
|||
if (bh->state == BUF_STATE_EMPTY && !get_some_more)
|
||||
break; // We stopped early
|
||||
if (bh->state == BUF_STATE_FULL) {
|
||||
smp_rmb();
|
||||
fsg->next_buffhd_to_drain = bh->next;
|
||||
bh->state = BUF_STATE_EMPTY;
|
||||
|
||||
|
|
@ -2359,6 +2375,7 @@ static int throw_away_data(struct fsg_dev *fsg)
|
|||
|
||||
/* Throw away the data in a filled buffer */
|
||||
if (bh->state == BUF_STATE_FULL) {
|
||||
smp_rmb();
|
||||
bh->state = BUF_STATE_EMPTY;
|
||||
fsg->next_buffhd_to_drain = bh->next;
|
||||
|
||||
|
|
@ -3024,6 +3041,7 @@ static int get_next_command(struct fsg_dev *fsg)
|
|||
if ((rc = sleep_thread(fsg)) != 0)
|
||||
return rc;
|
||||
}
|
||||
smp_rmb();
|
||||
rc = received_cbw(fsg, bh);
|
||||
bh->state = BUF_STATE_EMPTY;
|
||||
|
||||
|
|
@ -4072,7 +4090,6 @@ static int __init fsg_alloc(void)
|
|||
spin_lock_init(&fsg->lock);
|
||||
init_rwsem(&fsg->filesem);
|
||||
kref_init(&fsg->ref);
|
||||
init_waitqueue_head(&fsg->thread_wqh);
|
||||
init_completion(&fsg->thread_notifier);
|
||||
|
||||
the_fsg = fsg;
|
||||
|
|
|
|||
Loading…
Reference in New Issue