Commit Graph

185 Commits

Author SHA1 Message Date
Andrea Merello
d294d0286a rtl8187: make CTS-to-self protection work
CTS protection was not working properly because the HW needs
RTS flag to be asserted, and it need also RTS duration field to be
filled with CTS-to-self duration.

This patch makes the driver to do this.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-05-07 16:08:09 -04:00
Andrea Merello
5d0d1e9489 rtl8180: make CTS-to-self protection work
CTS protection was not working properly because the HW still need
RTS flag to be asserted, and it need also RTS rate field to be
set with CTS-to-self rate and RTS duration field to be filled with
CTS-to-self duration.

This patch makes the driver to do this.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-05-07 16:08:09 -04:00
Andrea Merello
e58342d9c8 rtl8180: report mac80211 short preamble RX flag
This patch make it possible to mac80211 to know whether a frame
has been received with short preamble.

It simply checks for the "splcp" flag in the RX status
descriptor, and eventually set RX_FLAG_SHORTPRE in mac80211
rx status structure.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-05-07 16:08:08 -04:00
Andrea Merello
97bd8c79da rtl8187: report mac80211 short preamble RX flag
This patch make it possible to mac80211 to know whether a frame
has been received with short preamble.

It simply checks for the "splcp" flag in the RX status
descriptor, and eventually set RX_FLAG_SHORTPRE in mac80211
rx status structure.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-05-07 16:08:08 -04:00
Andrea Merello
294bc611ab rtl8180: be paranoid in stopping unused queues.
HW should never attempt to perform DMA for unused queues.
For rtl8187se this is ensured by setting a dedicated register at
init time, before enabling TX.

In rtl8180/5 the register is only written at the first TX (because
in rtl8180/5 it serves also to kick DMA for used queues).
This should be enough, but it's worth to add a register write at
init time, before enabling TX.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-04-22 15:06:27 -04:00
Andrea Merello
6bcb20c776 rtl8180: add parentheses to REG_ADDR macros
Parentheses are missing around the macro argument, causing the
macro possibly not to work passing certain expressions as
arguments.

This should not cause any issues with current code, however it's
worth to add them, as a good practice, and to eventually avoid
future bugs.

Suggested-by: Dave Kilroy <kilroyd@googlemail.com>
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-04-22 15:06:27 -04:00
Andrea Merello
1c3fb9b8f8 rtl8180: fix enabled interrupt mask for rtl8187se
When preparing the bitfield to write to HW register, the high-priority
queue error interrupt bit is set two times, and the beacon queue
TX-OK interrupt is not enabled.

Currently this have no functional impact because the high-priority
queue is not used at all, and the beacon queue is not used yet.

This patch removes high-priority queue bits and it adds the
beacon queue missing bit.
It removes also the management queue bits because it is not used.

This was found by static code analyzer.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-04-22 15:06:27 -04:00
Larry Finger [ original patch ]
222aaffe12 rtl8180: change module name in rtl818x_pci
rtl8180 driver can handle also rtl8185 and rtl8187SE cards,
however in userspace tools (network manager) it still appares
as "rtl8180".
This might lead the user to think the wrong driver is in use.

This patch changes module name to "rtl818x_pci" that should be
more explanatory.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> [ original patch ]
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-04-22 15:06:27 -04:00
Alexey Khoroshilov
a31267c308 rtl8187: fix use after free on failure path in rtl8187_probe()
If allocation of io_dmabuf fails, rtl8187_probe() calls usb_put_dev(udev)
while usb_get_dev(udev) is not called yet. As a result refcnt is decremented
incorrectly and usb_dev can be used after memory deallocation.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-31 13:47:41 -04:00
Andrea Merello
6cea5f2173 rtl8180: don't use weird trick to access "far" registers
In rtl8180/rtl8185/rtl8187se the register space is represented
using packed structure type. Register are thus accessed using a
pointer of this type.
All registers are packed toghether, and only small gaps are present.

However Rtl8187se has also some "sparse" registers, very far from
the "main register block".

It could be possible to access them by simply declare huge reserved
blocks inside the register struct (and this causes NO memory waste).
However, for various reasons, access to those "far" registers is
done with special dedicated macros, without declaring them in the
register struct.

This is done in an intricate manner, that makes code less readable
and caused static analisys tool to produce warnings.

This patch keeps the "macro" mechanism, but it changes its
implementation in a simplier and more straightforward way.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-31 13:47:41 -04:00
Andrea Merello
aabcaa8b49 rtl8187: fix compile warning
ANAPARAM3 register, defined in the rtl818x common register
struct, is accessed as 16bit by rtl8187se and as 8bit by rtl8187b.
Since I have no documentation about this, I can only stick to
the reference code and to what is known to work.

This issue has been addressed by a patch from Larry Finger
that introduces an "union", in the register struct.
In my last patch-set I applied it on the register struct, but
I forget to update rtl8187 driver too.
This patch does it.

Suggested-by: Larry Finger <Larry.Finger@lwfinger.net> [ Original patch ]
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-31 13:47:41 -04:00
Andrea Merello
9d2ffb8160 rtl818x: Update Kconfig for rtl8187se
update description in Kconfig to state rtl8180 driver
now supports also rtl8187se cards

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:10 -04:00
Andrea Merello
1eba648f99 rtl8180: enable rtl8187se support
Finally make rtl8187se works (hopefylly).
This patch adds PCI ID for rtl8187, updates copyright notes and
updates MODULE_DESCRIPTION.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:09 -04:00
Andrea Merello
24b5fbf9d8 rtl8180: detect rtl8187se card
Add case to detect the rtl8187se card and its RF frontend.
In this case set also accordingly mac80211 queue number.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:09 -04:00
Andrea Merello
e944b0af86 rtl8180: add WMM parameters configuration for rtl8187se
Introduce a new function to configure AC parameters for TX queues
on rtl8187se cards, and hook it onto mac80211 in order to enable
WMM support.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:09 -04:00
Andrea Merello
833d15ad01 rtl8180: make sure RTL818X_MSR_ENEDCA is set for rtl8187se
MSR register for rtl8187se must always have ENEDCA flag set.
Write it accordingly when updated on BSS change.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:09 -04:00
Andrea Merello
355668d23a rtl8180: add ERP configuration for rtl8187se
This patch adds ERP configuration support for rtl8187se to the
existing ERP configuration function.
It needs a different register offset and it must not apply
rtl8185 workaround.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:09 -04:00
Andrea Merello
4a67aa5d64 rtl8180: add rtl8187se HW initialization
This patch adds few functions that initializes extra stuff that
is present only in rtl8187se HW, and it modify the existing
HW initialization function where necessary

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:08 -04:00
Andrea Merello
711d4ed381 rtl8180: add RF code for rtl8225 zebra v4
This patch introduce new RF code for rtl8225 zebra v4 radio
frontend.

This code contains a lot of black magic and it can work probably
only with the radio embdedded in the rtl8187se single-chip.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:08 -04:00
Andrea Merello
ff3cbc2cb6 rtl8180: introduce functions for setting ANAPARAM 2 and 3 params
rtl8180 has one register for analog converters setting ,rtl8185 has
two and rtl8187se has three.
Setting those registers require more than a simple write, and for
one of them a function is already provided.
This patch introduces functions for the other two.
rtl8187se will use them. rtl8185 doesen't yet, but should

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:08 -04:00
Andrea Merello
fc32ac911e rtl8180: add rtl8187se params to eeprom reading
rtl8187se nees extra parameters to be read from the eeprom.
This patch adds support for it

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:08 -04:00
Andrea Merello
f1026df86a rtl8180: config carbus register for rtl8187se
configuration of carbus-related registers is different for
rtl8187se.
Introduce a dedicated function that does it for all cards in the
proper way

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:08 -04:00
Andrea Merello
3ee44d6011 rtl8180: add TX queue mapping and support for rtl8187se
This patch adds tx queue mapping for rtl8187se and a long comment
block about their usages.
It adapts the TX function to use that map and it sets properly
the TX descriptor rtl8187se-only fields

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:08 -04:00
Andrea Merello
f18f112bde rtl8180: don't write MAR registers for rtl8187se
MAR registers are not present in rtl8187se, and attempting to
write to them must be avoided

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:08 -04:00
Andrea Merello
732c893206 rtl8180: introduce functions to enable/disable ints and add support for rtl8187se
This patch introduces two dedicated functions for enabling and
disabling ints.
Support for rtl8187se is also added to them

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:07 -04:00
Andrea Merello
a373ebcb5a rtl8180: add ISR for rtl8187se
rtl8187se has more queues and different ISR flags.
This patch adds a separated ISR handler for rtl8187se

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:07 -04:00
Andrea Merello
21025920cc rtl8180: support for rtl8187se RX descriptors
Currently RX status descriptor and RX command descriptor are
represented using the same struct type.
This patch splits this by introducing different types for
rx status and command descriptor.
Doing this make it possible to handle rtl8187se RX descriptors
easier.
This patch do also this by adding specific cases where needed.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:07 -04:00
Andrea Merello
d209f3b473 rtl8180: add basic rate configuration support for rtl8187se
Basic rate configuration is a bit different for rtl8187se.
Adding this also fixes the gcc warning introduced in last patch
about unhandled case in switch.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:07 -04:00
Andrea Merello
ac546bfb30 rtl8180: add rtl8187se fields to TX descriptor
This patch modifies the TX descriptor struct so it can work also
for rtl8187se.
Some reserved field is now meaningful, and where needed union is
used.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:07 -04:00
Andrea Merello
20296bf062 rtl8180: add rtl8187se chip type
Add back rtl8187se chip type to the enum for known chips.
This causes unhandled switch/case warning that will be fixed
in following patch

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:07 -04:00
Andrea Merello
247341e659 rtl818x: add registers for rtl8187se
Adds registers for rtl8187se to the rtl818x common struct

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:06 -04:00
Andrea Merello
fd6564fcdc rtl8180: rationalize TX queues
On currently supported HW there are four TX queues (three for normal
packets and one for beacons).

The driver uses just one TX queue, and declare to mac80211 to
support just one queue, but it allocates coherent memory for all
queues.
Furthermore the TX is code is written assumimg four queues exists,
and even if we decide to enable more queues in future, its mapping
rule to mac80211 is fixed.

This means we have memory waste on rtl8180/rtl8185, and we have also
not enough flexibility to add support for boards (rtl8187se) that
will use more queues.

This patch changes things in order to allocate coherent memory only
for the queues effectively used and it make it possible to specify
how to map hardware queues on mac80211 queues, that will be used
by rtl8187se code as soon it will be merged.

Note: even if the beacon queue is currently unused, this should
change, so I kept it.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:04 -04:00
Andrea Merello
4818d82899 rtl8180: fix DMA register are written two times
Hw DMA registers are written in rtl8180_init_hw function.
They are also written again just after calling rtl8180_init_hw.
There is no point in doing this twice.

Remove those redundant register writes from rtl8180_start.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-27 14:20:04 -04:00
Andrea Merello
8ace189d1a rtl818x: remove unused conf_erp callback from RF ops struct
The ERP configuration is now done outside RF code in both rtl8180
and rtl8187 drivers.

The conf_erp callback in common RF ops struct is now useless.
Remove it.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-19 15:15:46 -04:00
Andrea Merello
7d4b829a93 rtl8180: move eeprom read stuff in a separate function
Eeprom read operations are mixed in the probe function.
Make the code more readable and clean by extracting this code and
moving it in a dedicated function.

The variable eeprom_cck_table_adr, now useless, is here because
it will be needed for rtl8187se support, that I hope to add soon.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-17 13:44:15 -04:00
Andrea Merello
9069af794e rtl8180: make *IFS and CW tunable by mac80211, and set them in the proper place
SLOT, SIFS, DIFS, EIFS, CW and ACK-timeout registers are set in an
RF-code callback and their values are fixed.

This patch moves this off the rf-code, and introduce two new functions
that calculate these values depending by slot time and CW values
requested by mac80211.

This seems to improve performances on my setup.

Currently the ack and slot time values could be stored in a local
variable, but this patch stores it in the driver "priv" structure
because it will be useful for rtl8187se support that will be added
(hopefully) soon.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-17 13:44:15 -04:00
Andrea Merello
516a093019 rtl8180: support for BSS_CHANGED_BASIC_RATES
Basic rates setting is done with hardcoded register write with
fixed settings.

This patch introduces a new function that makes it possible to
configure basic rates and it add a check for mac80211
BSS_CHANGED_BASIC_RATES flag in order to eventually invoke that
function when needed.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-17 13:44:15 -04:00
Andrea Merello
bf888184f8 rtl8180: remove too-early-added rtl8187se enum value
While changing board-type variable to enum, I have added enum
value for rtl8187se by mistake.
This will causes gcc warnings with unhandled switch/cases.

Remove it temporarily until I will push also rtl8187se changes.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-17 13:44:15 -04:00
Andrea Merello
6caefd1271 rtl8180: prepare to handle more than two chip types
Currently a "r8185" integer variable is used as a boolean flag to
indicate whether the card is a rtl8185 or not.
Since now the driver supports only rtl8185 and rtl8180 cards, if
"r8185" variable is zero then the card is implicitly assumed to
be a rtl8180.

Now I'm preparing to add support for a third card type (rtl8187se).

This patch changes the "r8185" flag with an enum variable to
explicitly indicate which card type we have.

I'm submitting this this patch now, even if I still have to submit
other patches that not pertain with rtl8187se support, because
IMHO it's not worth rebasing them on the current code, using r8185
flag, and then changing them back again nearly immediately.
BTW if someone feels I really should do this, please tell me..

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-14 14:49:14 -04:00
andrea merello
c24782e612 rtl818x: make sure TX descriptor writes are done before kicking DMA
The TX descriptors are consumed by the HW using DMA.
Even if in the driver code the TX descriptor writes appears before
the HW "dma kick" register writes, the CPU may reorder them.

If this happens, the TX may not happen at all becase the "valid"
descriptor flag may have not been set yet.

This patch adds a write memory barrier to ensures the TX
descriptor is written before writing to the HW "dma kick" register.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-04 13:09:42 -05:00
andrea merello
4c552a5be7 rtl818x: Make sure the TX descriptor "valid" flag is written by last
The TX descriptors are consumed by the HW using DMA.
Even if in the driver code the memory write that sets the "valid"
flag appears after all other writes, the CPU may reorder writes,
causing the HW to consider as valid a not-fully-written yet
descriptor.

This may cause HW incorrect behaviour.

This can happen because (AFAIK) the HW may attempt DMA
asynchronously without waiting to be kicked by the following
register write.

This patch adds a write memory barrier to enforce writes ordering.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-03-04 13:07:52 -05:00
John W. Linville
f3b6a488a6 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless
Conflicts:
	drivers/net/wireless/ath/ath9k/recv.c
	drivers/net/wireless/mwifiex/pcie.c
2014-03-04 13:05:12 -05:00
andrea merello
14c76150f7 rtl818x: add comments to explain few not obvious HW configs.
Certain HW options (TX packet retry count, CW configuration and
TX power configuration) can be specified in both the TX packet
descriptor and also into HW "global" registers.

The HW is thus configured to honour the global register or the
TX descriptor field depending by the case.

This patch adds few comments that hopefully clarify in which cases
the driver uses one method and in which cases it uses the other.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-28 14:08:28 -05:00
andrea merello
4da18bb4fb rtl818x: make dev_alloc_skb() null pointer check to really work
During driver initialization, some skbs are preallocated for RX.
Currenly if the allocation fails, the driver's allocation routine
exits immediatly but it will return zero (success) anyway.

In this way the driver will continue initialization with buggy
pointers around.

This patch makes the driver's allocation routine to return
an error value and to print a complaint message when skb allocation
fails.
In this way its caller will not go further, avoinding the driver to
successfully load, and preventing dereferencing buggy pointers.

An hint is thus printed about why the driver failed.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-28 14:08:28 -05:00
andrea merello
ec1da08dd7 rtl818x: check for pci_map_single() success when initializing RX ring
During initialization a number of RX skbs are allocated and mapped
for DMA.
Currently if pci_map_single() fails, it will result in passing to the
HW a wrong DMA address (to write to!).

This patch adds check for this condition and eventually causes the
driver not to initialize, avoiding at least dangerous DMAs.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-28 14:08:27 -05:00
andrea merello
0269da2815 rtl818x: pci_iomap() should pair with pci_iounmap()
Currently the driver uses pci_iomap() but iounmap() is called in
the error path

Change to use pci_iounmap() instead.

Reported-by: Huqiu Liu <liuhq11@mails.tsinghua.edu.cn>
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-28 14:08:27 -05:00
andrea merello
e74075a936 rtl818x: Explicitly enable contetion window
Currently the contention window enable/disable HW flag is not
touched by the driver.

This patch explicitly set it to the correct value to make sure
contention window is enabled (AFAIK contention window must be
enabled in most (if not all) cases.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-28 14:08:27 -05:00
Stanislaw Gruszka
b6213e413a rtl8187: fix regression on MIPS without coherent DMA
This patch fixes regression caused by commit a16dad7763 "MIPS: Fix
potencial corruption". That commit fixes one corruption scenario in
cost of adding another one, which actually start to cause crashes
on Yeeloong laptop when rtl8187 driver is used.

For correct DMA read operation on machines without DMA coherence, kernel
have to invalidate cache, such it will refill later with new data that
device wrote to memory, when that data is needed to process. We can only
invalidate full cache line. Hence when cache line includes both dma
buffer and some other data (written in cache, but not yet in main
memory), the other data can not hit memory due to invalidation. That
happen on rtl8187 where struct rtl8187_priv fields are located just
before and after small buffers that are passed to USB layer and DMA
is performed on them.

To fix the problem we align buffers and reserve space after them to make
them match cache line.

This patch does not resolve all possible MIPS problems entirely, for
that we have to assure that we always map cache aligned buffers for DMA,
what can be complex or even not possible. But patch fixes visible and
reproducible regression and seems other possible corruptions do not
happen in practice, since Yeeloong laptop works stable without rtl8187
driver.

Bug report:
https://bugzilla.kernel.org/show_bug.cgi?id=54391

Reported-by: Petr Pisar <petr.pisar@atlas.cz>
Bisected-by: Tom Li <biergaizi2009@gmail.com>
Reported-and-tested-by: Tom Li <biergaizi2009@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Acked-by: Larry Finger <Larry.Finger@lwfinger.next>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-13 14:58:12 -05:00
John W. Linville
0e028ab0fb Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2014-02-13 14:43:02 -05:00
andrea merello
6f7343d4c4 rtl818x: change misleading names for few register bit definitions
In rtl8180/rtl8187 drivers, few register bit definitions have
names of form FOOBAR_SHIFT, suggesting they should be used as
shift offset, for example
reg |= (1 << ENABLE_FOO_SHIFT).

However they are actually defined as (1 << x) and thus they are
used (correctly) like
reg |= ENABLE_FOO_SHIFT;

This patch kills the misleading _SHIFT suffix.

Signed-off-by: andrea merello <andrea.merello@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-12 15:31:49 -05:00