Writing beacon to device happen through multiple write command calls.
zd_usb_iowrite16v uses synchronous urb call and with multiple write
commands in row causes high CPU usage.
This patch makes zd_usb_iowrite16v use asynchronous urb submit within
zd_usb.c. zd_usb_iowrite16v_async_start is used to initiate writing
multiple commands to device using zd_usb_iowrite16v_async. Each URB
is delayed and submitted to device by next zd_usb_iowrite16v_async
call or by call to zd_usb_iowrite16v_async_end. URBs submitted by
zd_usb_iowrite16v_async have URB_NO_INTERRUPT set and last URB
send by zd_usb_iowrite16v_async_end does not. This lower CPU
usage when doing writes that require multiple URBs.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@xxxxxxxx>
---
drivers/net/wireless/zd1211rw/zd_usb.c | 162 +++++++++++++++++++++++++++-----
drivers/net/wireless/zd1211rw/zd_usb.h | 5 +
2 files changed, 142 insertions(+), 25 deletions(-)
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index 7346512..c98f6e7 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -1156,6 +1156,7 @@ void zd_usb_init(struct zd_usb *usb, struct ieee80211_hw *hw,
memset(usb, 0, sizeof(*usb));
usb->intf = usb_get_intf(intf);
usb_set_intfdata(usb->intf, hw);
+ init_usb_anchor(&usb->submitted_cmds);
init_usb_interrupt(usb);
init_usb_tx(usb);
init_usb_rx(usb);
@@ -1663,13 +1664,104 @@ error:
return r;
}
-int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
- unsigned int count)
+static void iowrite16v_urb_complete(struct urb *urb)
+{
+ struct zd_usb *usb = urb->context;
+
+ if (urb->status && !usb->cmd_error)
+ usb->cmd_error = urb->status;
+}
+
+static int zd_submit_waiting_urb(struct zd_usb *usb, bool last)
+{
+ int r;
+ struct urb *urb = usb->urb_async_waiting;
+
+ if (!urb)
+ return 0;
+
+ usb->urb_async_waiting = NULL;
+
+ if (!last)
+ urb->transfer_flags |= URB_NO_INTERRUPT;
+
+ usb_anchor_urb(urb, &usb->submitted_cmds);
+ r = usb_submit_urb(urb, GFP_KERNEL);
+ if (r) {
+ usb_unanchor_urb(urb);
+ dev_dbg_f(zd_usb_dev(usb),
+ "error in usb_submit_urb(). Error number %d\n", r);
+ goto error;
+ }
+
+ /* fall-through with r == 0 */
+error:
+ usb_free_urb(urb);
+ return r;
+}
+
+static void zd_usb_iowrite16v_async_start(struct zd_usb *usb)
+{
+ ZD_ASSERT(usb_anchor_empty(&usb->submitted_cmds));
+ ZD_ASSERT(usb->urb_async_waiting == NULL);
+ ZD_ASSERT(!usb->in_async);
+
+ ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
+
+ usb->in_async = 1;
+ usb->cmd_error = 0;
+ usb->urb_async_waiting = NULL;
+}
+
+static int zd_usb_iowrite16v_async_end(struct zd_usb *usb, unsigned int timeout)
+{
+ int r;
+
+ ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
+ ZD_ASSERT(usb->in_async);
+
+ /* Submit last iowrite16v URB */
+ r = zd_submit_waiting_urb(usb, true);
+ if (r) {
+ dev_dbg_f(zd_usb_dev(usb),
+ "error in zd_submit_waiting_usb(). "
+ "Error number %d\n", r);
+
+ usb_kill_anchored_urbs(&usb->submitted_cmds);
+ goto error;
+ }
+
+ if (timeout)
+ timeout = usb_wait_anchor_empty_timeout(&usb->submitted_cmds,
+ timeout);
+ if (!timeout) {
+ usb_kill_anchored_urbs(&usb->submitted_cmds);
+ if (usb->cmd_error == -ENOENT) {
+ dev_dbg_f(zd_usb_dev(usb), "timed out");
+ r = -ETIMEDOUT;
+ goto error;
+ }
+ }
+
+ r = usb->cmd_error;
+error:
+ usb->in_async = 0;
+ return r;
+}
+
+static int zd_usb_iowrite16v_async(struct zd_usb *usb,
+ const struct zd_ioreq16 *ioreqs,
+ unsigned int count)
{
int r;
struct usb_device *udev;
struct usb_req_write_regs *req = NULL;
- int i, req_len, actual_req_len;
+ int i, req_len;
+ struct urb *urb;
+ struct usb_host_endpoint *ep;
+
+ ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
+ ZD_ASSERT(usb->in_async);
if (count == 0)
return 0;
@@ -1685,17 +1777,23 @@ int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
return -EWOULDBLOCK;
}
- ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
- BUILD_BUG_ON(sizeof(struct usb_req_write_regs) +
- USB_MAX_IOWRITE16_COUNT * sizeof(struct reg_data) >
- sizeof(usb->req_buf));
- BUG_ON(sizeof(struct usb_req_write_regs) +
- count * sizeof(struct reg_data) >
- sizeof(usb->req_buf));
+ udev = zd_usb_to_usbdev(usb);
+
+ ep = usb_pipe_endpoint(udev, usb_sndintpipe(udev, EP_REGS_OUT));
+ if (!ep)
+ return -ENOENT;
+
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb)
+ return -ENOMEM;
req_len = sizeof(struct usb_req_write_regs) +
count * sizeof(struct reg_data);
- req = (void *)usb->req_buf;
+ req = kmalloc(req_len, GFP_KERNEL);
+ if (!req) {
+ r = -ENOMEM;
+ goto error;
+ }
req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
for (i = 0; i < count; i++) {
@@ -1704,28 +1802,44 @@ int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
rw->value = cpu_to_le16(ioreqs[i].value);
}
- udev = zd_usb_to_usbdev(usb);
- r = usb_interrupt_msg(udev, usb_sndintpipe(udev, EP_REGS_OUT),
- req, req_len, &actual_req_len, 50 /* ms */);
+ usb_fill_int_urb(urb, udev, usb_sndintpipe(udev, EP_REGS_OUT),
+ req, req_len, iowrite16v_urb_complete, usb,
+ ep->desc.bInterval);
+ urb->transfer_flags |= URB_FREE_BUFFER | URB_SHORT_NOT_OK;
+
+ /* Submit previous URB */
+ r = zd_submit_waiting_urb(usb, false);
if (r) {
dev_dbg_f(zd_usb_dev(usb),
- "error in usb_interrupt_msg(). Error number %d\n", r);
- goto error;
- }
- if (req_len != actual_req_len) {
- dev_dbg_f(zd_usb_dev(usb),
- "error in usb_interrupt_msg()"
- " req_len %d != actual_req_len %d\n",
- req_len, actual_req_len);
- r = -EIO;
+ "error in zd_submit_waiting_usb(). "
+ "Error number %d\n", r);
goto error;
}
- /* FALL-THROUGH with r == 0 */
+ /* Delay submit so that URB_NO_INTERRUPT flag can be set for all URBs
+ * of currect batch except for very last.
+ */
+ usb->urb_async_waiting = urb;
+ return 0;
error:
+ usb_free_urb(urb);
return r;
}
+int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
+ unsigned int count)
+{
+ int r;
+
+ zd_usb_iowrite16v_async_start(usb);
+ r = zd_usb_iowrite16v_async(usb, ioreqs, count);
+ if (r) {
+ zd_usb_iowrite16v_async_end(usb, 0);
+ return r;
+ }
+ return zd_usb_iowrite16v_async_end(usb, 50 /* ms */);
+}
+
int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
{
int r;
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.h b/drivers/net/wireless/zd1211rw/zd_usb.h
index 2d688f4..9291426 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.h
+++ b/drivers/net/wireless/zd1211rw/zd_usb.h
@@ -217,8 +217,11 @@ struct zd_usb {
struct zd_usb_rx rx;
struct zd_usb_tx tx;
struct usb_interface *intf;
+ struct usb_anchor submitted_cmds;
+ struct urb *urb_async_waiting;
+ int cmd_error;
u8 req_buf[64]; /* zd_usb_iowrite16v needs 62 bytes */
- u8 is_zd1211b:1, initialized:1, was_running:1;
+ u8 is_zd1211b:1, initialized:1, was_running:1, in_async:1;
};
#define zd_usb_dev(usb) (&usb->intf->dev)
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
