From 834f41b0b2cb88517134c3304335483bc38ad8ff Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Tue, 11 Feb 2014 15:00:36 +0000 Subject: [PATCH] rtl8187: fix crashes on mips caused by misaligned DMA and cache issues Signed-off-by: Felix Fietkau SVN-Revision: 39570 --- .../mac80211/patches/300-pending_work.patch | 73 +++++++++++++++++++ 1 file changed, 73 insertions(+) diff --git a/package/kernel/mac80211/patches/300-pending_work.patch b/package/kernel/mac80211/patches/300-pending_work.patch index 4fc2e090df..52db79f408 100644 --- a/package/kernel/mac80211/patches/300-pending_work.patch +++ b/package/kernel/mac80211/patches/300-pending_work.patch @@ -1,3 +1,43 @@ +commit d4426800f71e972feaa33e04c5801fc730627bdd +Author: Stanislaw Gruszka +Date: Mon Feb 10 22:38:28 2014 +0100 + + rtl8187: fix regression on MIPS without coherent DMA + + 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 + Bisected-by: Tom Li + Reported-and-tested-by: Tom Li + Cc: stable@vger.kernel.org + Signed-off-by: Stanislaw Gruszka + commit e2f141d67ad1e7fe10aaab61811e8a409dfb2442 Author: Sujith Manoharan Date: Fri Feb 7 10:29:55 2014 +0530 @@ -2632,3 +2672,36 @@ Date: Thu Jan 23 20:06:34 2014 +0100 /* Revert chainmask to runtime parameters */ ar9003_hw_set_chain_masks(ah, ah->rxchainmask, ah->txchainmask); +--- 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 ++ + #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; + }; -- 2.30.2