zd1211rw: move async iowrite16v up to callers

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.

Make asynchronous zd_usb_iowrite16v_async available outside zd_usb.c
and use where possible.

This lower CPU usage from ~10% to ~2% on Intel Atom when running
AP-mode with 100 TU beacon interval.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 37 insertions, 13 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_chip.c b/drivers/net/wireless/zd1211rw/zd_chip.c
index 54f68f134ea..a73a305d3cb 100644
--- a/drivers/net/wireless/zd1211rw/zd_chip.c
+++ b/drivers/net/wireless/zd1211rw/zd_chip.c
@@ -142,8 +142,9 @@ int zd_ioread32v_locked(struct zd_chip *chip, u32 *values, const zd_addr_t *addr
         return 0;
 }
 
-int _zd_iowrite32v_locked(struct zd_chip *chip, const struct zd_ioreq32 *ioreqs,
-                   unsigned int count)
+static int _zd_iowrite32v_async_locked(struct zd_chip *chip,
+                                       const struct zd_ioreq32 *ioreqs,
+                                       unsigned int count)
 {
         int i, j, r;
         struct zd_ioreq16 ioreqs16[USB_MAX_IOWRITE32_COUNT * 2];
@@ -170,7 +171,7 @@ int _zd_iowrite32v_locked(struct zd_chip *chip, const struct zd_ioreq32 *ioreqs,
                 ioreqs16[j+1].addr  = ioreqs[i].addr;
         }
 
-        r = zd_usb_iowrite16v(&chip->usb, ioreqs16, count16);
+        r = zd_usb_iowrite16v_async(&chip->usb, ioreqs16, count16);
 #ifdef DEBUG
         if (r) {
                 dev_dbg_f(zd_chip_dev(chip),
@@ -180,6 +181,20 @@ int _zd_iowrite32v_locked(struct zd_chip *chip, const struct zd_ioreq32 *ioreqs,
         return r;
 }
 
+int _zd_iowrite32v_locked(struct zd_chip *chip, const struct zd_ioreq32 *ioreqs,
+                          unsigned int count)
+{
+        int r;
+
+        zd_usb_iowrite16v_async_start(&chip->usb);
+        r = _zd_iowrite32v_async_locked(chip, ioreqs, count);
+        if (r) {
+                zd_usb_iowrite16v_async_end(&chip->usb, 0);
+                return r;
+        }
+        return zd_usb_iowrite16v_async_end(&chip->usb, 50 /* ms */);
+}
+
 int zd_iowrite16a_locked(struct zd_chip *chip,
                   const struct zd_ioreq16 *ioreqs, unsigned int count)
 {
@@ -187,6 +202,8 @@ int zd_iowrite16a_locked(struct zd_chip *chip,
         unsigned int i, j, t, max;
 
         ZD_ASSERT(mutex_is_locked(&chip->mutex));
+        zd_usb_iowrite16v_async_start(&chip->usb);
+
         for (i = 0; i < count; i += j + t) {
                 t = 0;
                 max = count-i;
@@ -199,8 +216,9 @@ int zd_iowrite16a_locked(struct zd_chip *chip,
                         }
                 }
 
-                r = zd_usb_iowrite16v(&chip->usb, &ioreqs[i], j);
+                r = zd_usb_iowrite16v_async(&chip->usb, &ioreqs[i], j);
                 if (r) {
+                        zd_usb_iowrite16v_async_end(&chip->usb, 0);
                         dev_dbg_f(zd_chip_dev(chip),
                                   "error zd_usb_iowrite16v. Error number %d\n",
                                   r);
@@ -208,7 +226,7 @@ int zd_iowrite16a_locked(struct zd_chip *chip,
                 }
         }
 
-        return 0;
+        return zd_usb_iowrite16v_async_end(&chip->usb, 50 /* ms */);
 }
 
 /* Writes a variable number of 32 bit registers. The functions will split
@@ -221,6 +239,8 @@ int zd_iowrite32a_locked(struct zd_chip *chip,
         int r;
         unsigned int i, j, t, max;
 
+        zd_usb_iowrite16v_async_start(&chip->usb);
+
         for (i = 0; i < count; i += j + t) {
                 t = 0;
                 max = count-i;
@@ -233,8 +253,9 @@ int zd_iowrite32a_locked(struct zd_chip *chip,
                         }
                 }
 
-                r = _zd_iowrite32v_locked(chip, &ioreqs[i], j);
+                r = _zd_iowrite32v_async_locked(chip, &ioreqs[i], j);
                 if (r) {
+                        zd_usb_iowrite16v_async_end(&chip->usb, 0);
                         dev_dbg_f(zd_chip_dev(chip),
                                 "error _zd_iowrite32v_locked."
                                 " Error number %d\n", r);
@@ -242,7 +263,7 @@ int zd_iowrite32a_locked(struct zd_chip *chip,
                 }
         }
 
-        return 0;
+        return zd_usb_iowrite16v_async_end(&chip->usb, 50 /* ms */);
 }
 
 int zd_ioread16(struct zd_chip *chip, zd_addr_t addr, u16 *value)
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index c98f6e7eed3..81e80489a05 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -1674,7 +1674,7 @@ static void iowrite16v_urb_complete(struct urb *urb)
 
 static int zd_submit_waiting_urb(struct zd_usb *usb, bool last)
 {
-        int r;
+        int r = 0;
         struct urb *urb = usb->urb_async_waiting;
 
         if (!urb)
@@ -1700,7 +1700,7 @@ error:
         return r;
 }
 
-static void zd_usb_iowrite16v_async_start(struct zd_usb *usb)
+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);
@@ -1713,7 +1713,7 @@ static void zd_usb_iowrite16v_async_start(struct zd_usb *usb)
         usb->urb_async_waiting = NULL;
 }
 
-static int zd_usb_iowrite16v_async_end(struct zd_usb *usb, unsigned int timeout)
+int zd_usb_iowrite16v_async_end(struct zd_usb *usb, unsigned int timeout)
 {
         int r;
 
@@ -1749,9 +1749,8 @@ error:
         return r;
 }
 
-static int zd_usb_iowrite16v_async(struct zd_usb *usb,
-                                   const struct zd_ioreq16 *ioreqs,
-                                   unsigned int count)
+int zd_usb_iowrite16v_async(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
+                            unsigned int count)
 {
         int r;
         struct usb_device *udev;
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.h b/drivers/net/wireless/zd1211rw/zd_usb.h
index 92914269206..b3df2c8116c 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.h
+++ b/drivers/net/wireless/zd1211rw/zd_usb.h
@@ -273,6 +273,10 @@ static inline int zd_usb_ioread16(struct zd_usb *usb, u16 *value,
         return zd_usb_ioread16v(usb, value, (const zd_addr_t *)&addr, 1);
 }
 
+void zd_usb_iowrite16v_async_start(struct zd_usb *usb);
+int zd_usb_iowrite16v_async_end(struct zd_usb *usb, unsigned int timeout);
+int zd_usb_iowrite16v_async(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
+                            unsigned int count);
 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
                       unsigned int count);