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authorLarry Finger <Larry.Finger@lwfinger.net>2012-07-11 14:37:28 -0500
committerJohn W. Linville <linville@tuxdriver.com>2012-07-12 15:27:18 -0400
commit3ce4d85b76010525adedcc2555fa164bf706a2f3 (patch)
tree05f3f6410bc376e7a28f0d9fcca686993e65591a /drivers/net/wireless/rtlwifi/usb.c
parent2a00def4d6e50cbfa7588887fdbe2a97042e42bb (diff)
downloadop-kernel-dev-3ce4d85b76010525adedcc2555fa164bf706a2f3.zip
op-kernel-dev-3ce4d85b76010525adedcc2555fa164bf706a2f3.tar.gz
rtlwifi: rtl8192cu: Change buffer allocation for synchronous reads
In commit a7959c1, the USB part of rtlwifi was switched to convert _usb_read_sync() to using a preallocated buffer rather than one that has been acquired using kmalloc. Although this routine is named as though it were synchronous, there seem to be simultaneous users, and the selection of the index to the data buffer is not multi-user safe. This situation is addressed by adding a new spinlock. The routine cannot sleep, thus a mutex is not allowed. Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Stable <stable@vger.kernel.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net/wireless/rtlwifi/usb.c')
-rw-r--r--drivers/net/wireless/rtlwifi/usb.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c
index a6049d7..aa970fc 100644
--- a/drivers/net/wireless/rtlwifi/usb.c
+++ b/drivers/net/wireless/rtlwifi/usb.c
@@ -131,15 +131,19 @@ static u32 _usb_read_sync(struct rtl_priv *rtlpriv, u32 addr, u16 len)
u8 request;
u16 wvalue;
u16 index;
- __le32 *data = &rtlpriv->usb_data[rtlpriv->usb_data_index];
+ __le32 *data;
+ unsigned long flags;
+ spin_lock_irqsave(&rtlpriv->locks.usb_lock, flags);
+ if (++rtlpriv->usb_data_index >= RTL_USB_MAX_RX_COUNT)
+ rtlpriv->usb_data_index = 0;
+ data = &rtlpriv->usb_data[rtlpriv->usb_data_index];
+ spin_unlock_irqrestore(&rtlpriv->locks.usb_lock, flags);
request = REALTEK_USB_VENQT_CMD_REQ;
index = REALTEK_USB_VENQT_CMD_IDX; /* n/a */
wvalue = (u16)addr;
_usbctrl_vendorreq_sync_read(udev, request, wvalue, index, data, len);
- if (++rtlpriv->usb_data_index >= RTL_USB_MAX_RX_COUNT)
- rtlpriv->usb_data_index = 0;
return le32_to_cpu(*data);
}
@@ -951,6 +955,10 @@ int __devinit rtl_usb_probe(struct usb_interface *intf,
GFP_KERNEL);
if (!rtlpriv->usb_data)
return -ENOMEM;
+
+ /* this spin lock must be initialized early */
+ spin_lock_init(&rtlpriv->locks.usb_lock);
+
rtlpriv->usb_data_index = 0;
init_completion(&rtlpriv->firmware_loading_complete);
SET_IEEE80211_DEV(hw, &intf->dev);
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