diff options
| author | Manuel Lauss <manuel.lauss@googlemail.com> | 2010-01-26 20:39:33 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2010-02-01 20:30:25 +0100 |
| commit | 22f4bb68b301f4ab896e9b3b0431fdde962242d2 (patch) | |
| tree | 62767bbd1ad7d11dbbeea3482b7902f08ea178ce | |
| parent | be8cde8b24c9dca1e54598690115eee5b1476519 (diff) | |
MIPS: Alchemy: Fix dbdma ring destruction memory debugcheck.
DBDMA descriptors need to be located at 32-byte aligned addresses;
however kmalloc in conjunction with the SLAB allocator and
CONFIG_DEBUG_SLUB enabled doesn't deliver any. The dbdma code works
around that by allocating a larger area and realigning the start
address within it.
When freeing a channel however this adjustment is not taken into
account which results in an oops:
Kernel bug detected[#1]:
[...]
Call Trace:
[<80186010>] cache_free_debugcheck+0x284/0x318
[<801869d8>] kfree+0xe8/0x2a0
[<8010b31c>] au1xxx_dbdma_chan_free+0x2c/0x7c
[<80388dc8>] au1x_pcm_dbdma_free+0x34/0x4c
[<80388fa8>] au1xpsc_pcm_close+0x28/0x38
[<80383cb8>] soc_codec_close+0x14c/0x1cc
[<8036dbb4>] snd_pcm_release_substream+0x60/0xac
[<8036dc40>] snd_pcm_release+0x40/0xa0
[<8018c7a8>] __fput+0x11c/0x228
[<80188f60>] filp_close+0x7c/0x98
[<80189018>] sys_close+0x9c/0xe4
[<801022a0>] stack_done+0x20/0x3c
Fix this by recording the address delivered by kmalloc() and using
it as parameter to kfree().
This fix is only necessary with the SLAB allocator and CONFIG_DEBUG_SLAB
enabled; non-debug SLAB, SLUB do return nicely aligned addresses,
debug-enabled SLUB currently panics early in the boot process.
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/878/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| -rw-r--r-- | arch/mips/alchemy/common/dbdma.c | 7 | ||||
| -rw-r--r-- | arch/mips/include/asm/mach-au1x00/au1xxx_dbdma.h | 1 |
2 files changed, 6 insertions, 2 deletions
diff --git a/arch/mips/alchemy/common/dbdma.c b/arch/mips/alchemy/common/dbdma.c index 5c68569344c..f9201ca2295 100644 --- a/arch/mips/alchemy/common/dbdma.c +++ b/arch/mips/alchemy/common/dbdma.c @@ -412,8 +412,11 @@ u32 au1xxx_dbdma_ring_alloc(u32 chanid, int entries) if (desc_base == 0) return 0; + ctp->cdb_membase = desc_base; desc_base = ALIGN_ADDR(desc_base, sizeof(au1x_ddma_desc_t)); - } + } else + ctp->cdb_membase = desc_base; + dp = (au1x_ddma_desc_t *)desc_base; /* Keep track of the base descriptor. */ @@ -831,7 +834,7 @@ void au1xxx_dbdma_chan_free(u32 chanid) au1xxx_dbdma_stop(chanid); - kfree((void *)ctp->chan_desc_base); + kfree((void *)ctp->cdb_membase); stp->dev_flags &= ~DEV_FLAGS_INUSE; dtp->dev_flags &= ~DEV_FLAGS_INUSE; diff --git a/arch/mips/include/asm/mach-au1x00/au1xxx_dbdma.h b/arch/mips/include/asm/mach-au1x00/au1xxx_dbdma.h index 06f68f43800..d206000fbfe 100644 --- a/arch/mips/include/asm/mach-au1x00/au1xxx_dbdma.h +++ b/arch/mips/include/asm/mach-au1x00/au1xxx_dbdma.h @@ -305,6 +305,7 @@ typedef struct dbdma_chan_config { dbdev_tab_t *chan_dest; au1x_dma_chan_t *chan_ptr; au1x_ddma_desc_t *chan_desc_base; + u32 cdb_membase; /* kmalloc base of above */ au1x_ddma_desc_t *get_ptr, *put_ptr, *cur_ptr; void *chan_callparam; void (*chan_callback)(int, void *); |