3.10.30-gnu_0loongsonlibre

1 files changed, 85 insertions, 0 deletions

diff --git a/lemote/gnewsense/tags/3.10.30-gnu_0loongsonlibre/fix-rtl8187.patch b/lemote/gnewsense/tags/3.10.30-gnu_0loongsonlibre/fix-rtl8187.patch
new file mode 100644
index 000000000..44888a3f0
--- /dev/null
+++ b/lemote/gnewsense/tags/3.10.30-gnu_0loongsonlibre/fix-rtl8187.patch
@@ -0,0 +1,85 @@
+From: Stanislaw Gruszka <stf_xl@wp.pl>
+Subject: rtl8187: fix regression on MIPS without coherent DMA
+Date: 2014-02-10 21:38:28
+
+http://marc.info/?l=linux-wireless&m=139206817709511&w=2
+
+This patch fixes regression caused by commit a16dad77634 "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>
+---
+ drivers/net/wireless/rtl818x/rtl8187/rtl8187.h |   10 ++++++++--
+ 1 files changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h b/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h
+index 56aee06..a6ad79f 100644
+--- a/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h
++++ b/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h
+@@ -15,6 +15,8 @@
+ #ifndef RTL8187_H
+ #define RTL8187_H
+ 
++#include <linux/cache.h>
++
+ #include "rtl818x.h"
+ #include "leds.h"
+ 
+@@ -139,7 +141,10 @@ struct rtl8187_priv {
+ 	u8 aifsn[4];
+ 	u8 rfkill_mask;
+ 	struct {
+-		__le64 buf;
++		union {
++			__le64 buf;
++			u8 dummy1[L1_CACHE_BYTES];
++		} ____cacheline_aligned;
+ 		struct sk_buff_head queue;
+ 	} b_tx_status; /* This queue is used by both -b and non-b devices */
+ 	struct mutex io_mutex;
+@@ -147,7 +152,8 @@ struct rtl8187_priv {
+ 		u8 bits8;
+ 		__le16 bits16;
+ 		__le32 bits32;
+-	} *io_dmabuf;
++		u8 dummy2[L1_CACHE_BYTES];
++	} *io_dmabuf ____cacheline_aligned;
+ 	bool rfkill_off;
+ 	u16 seqno;
+ };
+-- 
+1.7.4.4
+
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