]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
rtlwifi: Preallocate USB read buffers and eliminate kalloc in read routine
authorLarry Finger <Larry.Finger@lwfinger.net>
Mon, 19 Mar 2012 20:44:31 +0000 (15:44 -0500)
committerJohn W. Linville <linville@tuxdriver.com>
Wed, 11 Apr 2012 19:01:44 +0000 (15:01 -0400)
commita7959c1394d4126a70a53b914ce4105f5173d0aa
tree62374a9502df20d3f5f949793ad870755f58c4b7
parent011afa1ed8c408d694957d2474d89dc81a60b70c
rtlwifi: Preallocate USB read buffers and eliminate kalloc in read routine

The current version of rtlwifi for USB operations uses kmalloc to
acquire a 32-bit buffer for each read of the device. When
_usb_read_sync() is called with the rcu_lock held, the result is
a "sleeping function called from invalid context" BUG. This is
reported for two cases in https://bugzilla.kernel.org/show_bug.cgi?id=42775.
The first case has the lock originating from within rtlwifi and could
be fixed by rearranging the locking; however, the second originates from
within mac80211. The kmalloc() call is removed from _usb_read_sync()
by creating a ring buffer pointer in the private area and
allocating the buffer data in the probe routine.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org> [This version good for 3.3+ - different patch for 3.2 - 2.6.39]
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/rtlwifi/usb.c
drivers/net/wireless/rtlwifi/wifi.h