rtl8187: use DMA-aware buffers with usb_control_msg

Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 62 insertions, 16 deletions

diff --git a/drivers/net/wireless/rtl818x/rtl8187.h b/drivers/net/wireless/rtl818x/rtl8187.h
index 9718f61809cf..edeff82a4d06 100644
--- a/drivers/net/wireless/rtl818x/rtl8187.h
+++ b/drivers/net/wireless/rtl818x/rtl8187.h
@@ -120,6 +120,12 @@ struct rtl8187_priv {
                 __le64 buf;
                 struct sk_buff_head queue;
         } b_tx_status; /* This queue is used by both -b and non-b devices */
+        struct mutex io_mutex;
+        union {
+                u8 bits8;
+                __le16 bits16;
+                __le32 bits32;
+        } *io_dmabuf;
 };
 
 void rtl8187_write_phy(struct ieee80211_hw *dev, u8 addr, u32 data);
@@ -129,10 +135,14 @@ static inline u8 rtl818x_ioread8_idx(struct rtl8187_priv *priv,
 {
         u8 val;
 
+        mutex_lock(&priv->io_mutex);
         usb_control_msg(priv->udev, usb_rcvctrlpipe(priv->udev, 0),
                         RTL8187_REQ_GET_REG, RTL8187_REQT_READ,
-                        (unsigned long)addr, idx & 0x03, &val,
-                        sizeof(val), HZ / 2);
+                        (unsigned long)addr, idx & 0x03,
+                        &priv->io_dmabuf->bits8, sizeof(val), HZ / 2);
+
+        val = priv->io_dmabuf->bits8;
+        mutex_unlock(&priv->io_mutex);
 
         return val;
 }
@@ -147,10 +157,14 @@ static inline u16 rtl818x_ioread16_idx(struct rtl8187_priv *priv,
 {
         __le16 val;
 
+        mutex_lock(&priv->io_mutex);
         usb_control_msg(priv->udev, usb_rcvctrlpipe(priv->udev, 0),
                         RTL8187_REQ_GET_REG, RTL8187_REQT_READ,
-                        (unsigned long)addr, idx & 0x03, &val,
-                        sizeof(val), HZ / 2);
+                        (unsigned long)addr, idx & 0x03,
+                        &priv->io_dmabuf->bits16, sizeof(val), HZ / 2);
+
+        val = priv->io_dmabuf->bits16;
+        mutex_unlock(&priv->io_mutex);
 
         return le16_to_cpu(val);
 }
@@ -165,10 +179,14 @@ static inline u32 rtl818x_ioread32_idx(struct rtl8187_priv *priv,
 {
         __le32 val;
 
+        mutex_lock(&priv->io_mutex);
         usb_control_msg(priv->udev, usb_rcvctrlpipe(priv->udev, 0),
                         RTL8187_REQ_GET_REG, RTL8187_REQT_READ,
-                        (unsigned long)addr, idx & 0x03, &val,
-                        sizeof(val), HZ / 2);
+                        (unsigned long)addr, idx & 0x03,
+                        &priv->io_dmabuf->bits32, sizeof(val), HZ / 2);
+
+        val = priv->io_dmabuf->bits32;
+        mutex_unlock(&priv->io_mutex);
 
         return le32_to_cpu(val);
 }
@@ -181,10 +199,15 @@ static inline u32 rtl818x_ioread32(struct rtl8187_priv *priv, __le32 *addr)
 static inline void rtl818x_iowrite8_idx(struct rtl8187_priv *priv,
                                         u8 *addr, u8 val, u8 idx)
 {
+        mutex_lock(&priv->io_mutex);
+
+        priv->io_dmabuf->bits8 = val;
         usb_control_msg(priv->udev, usb_sndctrlpipe(priv->udev, 0),
                         RTL8187_REQ_SET_REG, RTL8187_REQT_WRITE,
-                        (unsigned long)addr, idx & 0x03, &val,
-                        sizeof(val), HZ / 2);
+                        (unsigned long)addr, idx & 0x03,
+                        &priv->io_dmabuf->bits8, sizeof(val), HZ / 2);
+
+        mutex_unlock(&priv->io_mutex);
 }
 
 static inline void rtl818x_iowrite8(struct rtl8187_priv *priv, u8 *addr, u8 val)
@@ -195,12 +218,15 @@ static inline void rtl818x_iowrite8(struct rtl8187_priv *priv, u8 *addr, u8 val)
 static inline void rtl818x_iowrite16_idx(struct rtl8187_priv *priv,
                                          __le16 *addr, u16 val, u8 idx)
 {
-        __le16 buf = cpu_to_le16(val);
+        mutex_lock(&priv->io_mutex);
 
+        priv->io_dmabuf->bits16 = cpu_to_le16(val);
         usb_control_msg(priv->udev, usb_sndctrlpipe(priv->udev, 0),
                         RTL8187_REQ_SET_REG, RTL8187_REQT_WRITE,
-                        (unsigned long)addr, idx & 0x03, &buf, sizeof(buf),
-                        HZ / 2);
+                        (unsigned long)addr, idx & 0x03,
+                        &priv->io_dmabuf->bits16, sizeof(val), HZ / 2);
+
+        mutex_unlock(&priv->io_mutex);
 }
 
 static inline void rtl818x_iowrite16(struct rtl8187_priv *priv, __le16 *addr,
@@ -212,12 +238,15 @@ static inline void rtl818x_iowrite16(struct rtl8187_priv *priv, __le16 *addr,
 static inline void rtl818x_iowrite32_idx(struct rtl8187_priv *priv,
                                          __le32 *addr, u32 val, u8 idx)
 {
-        __le32 buf = cpu_to_le32(val);
+        mutex_lock(&priv->io_mutex);
 
+        priv->io_dmabuf->bits32 = cpu_to_le32(val);
         usb_control_msg(priv->udev, usb_sndctrlpipe(priv->udev, 0),
                         RTL8187_REQ_SET_REG, RTL8187_REQT_WRITE,
-                        (unsigned long)addr, idx & 0x03, &buf, sizeof(buf),
-                        HZ / 2);
+                        (unsigned long)addr, idx & 0x03,
+                        &priv->io_dmabuf->bits32, sizeof(val), HZ / 2);
+
+        mutex_unlock(&priv->io_mutex);
 }
 
 static inline void rtl818x_iowrite32(struct rtl8187_priv *priv, __le32 *addr,
diff --git a/drivers/net/wireless/rtl818x/rtl8187_dev.c b/drivers/net/wireless/rtl818x/rtl8187_dev.c
index fd81884b9c7d..bac6cfba6abd 100644
--- a/drivers/net/wireless/rtl818x/rtl8187_dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8187_dev.c
@@ -1329,6 +1329,14 @@ static int __devinit rtl8187_probe(struct usb_interface *intf,
         priv = dev->priv;
         priv->is_rtl8187b = (id->driver_info == DEVICE_RTL8187B);
 
+        /* allocate "DMA aware" buffer for register accesses */
+        priv->io_dmabuf = kmalloc(sizeof(*priv->io_dmabuf), GFP_KERNEL);
+        if (!priv->io_dmabuf) {
+                err = -ENOMEM;
+                goto err_free_dev;
+        }
+        mutex_init(&priv->io_mutex);
+
         SET_IEEE80211_DEV(dev, &intf->dev);
         usb_set_intfdata(intf, dev);
         priv->udev = udev;
@@ -1495,7 +1503,7 @@ static int __devinit rtl8187_probe(struct usb_interface *intf,
         err = ieee80211_register_hw(dev);
         if (err) {
                 printk(KERN_ERR "rtl8187: Cannot register device\n");
-                goto err_free_dev;
+                goto err_free_dmabuf;
         }
         mutex_init(&priv->conf_mutex);
         skb_queue_head_init(&priv->b_tx_status.queue);
@@ -1506,6 +1514,8 @@ static int __devinit rtl8187_probe(struct usb_interface *intf,
 
         return 0;
 
+ err_free_dmabuf:
+        kfree(priv->io_dmabuf);
  err_free_dev:
         ieee80211_free_hw(dev);
         usb_set_intfdata(intf, NULL);
@@ -1526,6 +1536,7 @@ static void __devexit rtl8187_disconnect(struct usb_interface *intf)
         priv = dev->priv;
         usb_reset_device(priv->udev);
         usb_put_dev(interface_to_usbdev(intf));
+        kfree(priv->io_dmabuf);
         ieee80211_free_hw(dev);
 }
 
diff --git a/drivers/net/wireless/rtl818x/rtl8187_rtl8225.c b/drivers/net/wireless/rtl818x/rtl8187_rtl8225.c
index 78df281b297a..a09819386a1e 100644
--- a/drivers/net/wireless/rtl818x/rtl8187_rtl8225.c
+++ b/drivers/net/wireless/rtl818x/rtl8187_rtl8225.c
@@ -88,9 +88,15 @@ static void rtl8225_write_8051(struct ieee80211_hw *dev, u8 addr, __le16 data)
         rtl818x_iowrite16(priv, &priv->map->RFPinsOutput, reg80);
         udelay(10);
 
+        mutex_lock(&priv->io_mutex);
+
+        priv->io_dmabuf->bits16 = data;
         usb_control_msg(priv->udev, usb_sndctrlpipe(priv->udev, 0),
                         RTL8187_REQ_SET_REG, RTL8187_REQT_WRITE,
-                        addr, 0x8225, &data, sizeof(data), HZ / 2);
+                        addr, 0x8225, &priv->io_dmabuf->bits16, sizeof(data),
+                        HZ / 2);
+
+        mutex_unlock(&priv->io_mutex);
 
         rtl818x_iowrite16(priv, &priv->map->RFPinsOutput, reg80 | (1 << 2));
         udelay(10);