From 2470191c9f2c754d9a8254803296e68ae1d1d8c8 Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Wed, 11 Jul 2012 14:37:28 -0500 Subject: [PATCH] rtlwifi: rtl8192cu: Change buffer allocation for synchronous reads In commit 6604d15, 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 Cc: Stable Signed-off-by: John W. Linville --- drivers/net/wireless/rtlwifi/usb.c | 14 +++++++++++--- drivers/net/wireless/rtlwifi/wifi.h | 1 + 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c index a6049d7d51b39..aa970fc18a217 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); diff --git a/drivers/net/wireless/rtlwifi/wifi.h b/drivers/net/wireless/rtlwifi/wifi.h index bd816aef26dcb..cdaa21f297108 100644 --- a/drivers/net/wireless/rtlwifi/wifi.h +++ b/drivers/net/wireless/rtlwifi/wifi.h @@ -1555,6 +1555,7 @@ struct rtl_locks { spinlock_t rf_ps_lock; spinlock_t rf_lock; spinlock_t waitq_lock; + spinlock_t usb_lock; /*Dual mac*/ spinlock_t cck_and_rw_pagea_lock; -- 2.39.5