linux.git/drivers/dma, branch v3.13-rc5 Linux kernel source tree net_dma: mark broken 2013-12-18T20:53:43+00:00 Dan Williams dan.j.williams@intel.com 2013-12-17T18:09:32+00:00 77873803363c9e831fc1d1e6895c084279090c22 net_dma can cause data to be copied to a stale mapping if a copy-on-write fault occurs during dma. The application sees missing data. The following trace is triggered by modifying the kernel to WARN if it ever triggers copy-on-write on a page that is undergoing dma: WARNING: CPU: 24 PID: 2529 at lib/dma-debug.c:485 debug_dma_assert_idle+0xd2/0x120() ioatdma 0000:00:04.0: DMA-API: cpu touching an active dma mapped page [pfn=0x16bcd9] Modules linked in: iTCO_wdt iTCO_vendor_support ioatdma lpc_ich pcspkr dca CPU: 24 PID: 2529 Comm: linbug Tainted: G W 3.13.0-rc1+ #353 00000000000001e5 ffff88016f45f688 ffffffff81751041 ffff88017ab0ef70 ffff88016f45f6d8 ffff88016f45f6c8 ffffffff8104ed9c ffffffff810f3646 ffff8801768f4840 0000000000000282 ffff88016f6cca10 00007fa2bb699349 Call Trace: [<ffffffff81751041>] dump_stack+0x46/0x58 [<ffffffff8104ed9c>] warn_slowpath_common+0x8c/0xc0 [<ffffffff810f3646>] ? ftrace_pid_func+0x26/0x30 [<ffffffff8104ee86>] warn_slowpath_fmt+0x46/0x50 [<ffffffff8139c062>] debug_dma_assert_idle+0xd2/0x120 [<ffffffff81154a40>] do_wp_page+0xd0/0x790 [<ffffffff811582ac>] handle_mm_fault+0x51c/0xde0 [<ffffffff813830b9>] ? copy_user_enhanced_fast_string+0x9/0x20 [<ffffffff8175fc2c>] __do_page_fault+0x19c/0x530 [<ffffffff8175c196>] ? _raw_spin_lock_bh+0x16/0x40 [<ffffffff810f3539>] ? trace_clock_local+0x9/0x10 [<ffffffff810fa1f4>] ? rb_reserve_next_event+0x64/0x310 [<ffffffffa0014c00>] ? ioat2_dma_prep_memcpy_lock+0x60/0x130 [ioatdma] [<ffffffff8175ffce>] do_page_fault+0xe/0x10 [<ffffffff8175c862>] page_fault+0x22/0x30 [<ffffffff81643991>] ? __kfree_skb+0x51/0xd0 [<ffffffff813830b9>] ? copy_user_enhanced_fast_string+0x9/0x20 [<ffffffff81388ea2>] ? memcpy_toiovec+0x52/0xa0 [<ffffffff8164770f>] skb_copy_datagram_iovec+0x5f/0x2a0 [<ffffffff8169d0f4>] tcp_rcv_established+0x674/0x7f0 [<ffffffff816a68c5>] tcp_v4_do_rcv+0x2e5/0x4a0 [..] ---[ end trace e30e3b01191b7617 ]--- Mapped at: [<ffffffff8139c169>] debug_dma_map_page+0xb9/0x160 [<ffffffff8142bf47>] dma_async_memcpy_pg_to_pg+0x127/0x210 [<ffffffff8142cce9>] dma_memcpy_pg_to_iovec+0x119/0x1f0 [<ffffffff81669d3c>] dma_skb_copy_datagram_iovec+0x11c/0x2b0 [<ffffffff8169d1ca>] tcp_rcv_established+0x74a/0x7f0: ...the problem is that the receive path falls back to cpu-copy in several locations and this trace is just one of the areas. A few options were considered to fix this: 1/ sync all dma whenever a cpu copy branch is taken 2/ modify the page fault handler to hold off while dma is in-flight Option 1 adds yet more cpu overhead to an "offload" that struggles to compete with cpu-copy. Option 2 adds checks for behavior that is already documented as broken when using get_user_pages(). At a minimum a debug mode is warranted to catch and flag these violations of the dma-api vs get_user_pages(). Thanks to David for his reproducer. Cc: <stable@vger.kernel.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Alexander Duyck <alexander.h.duyck@intel.com> Reported-by: David Whipple <whipple@securedatainnovations.ch> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
net_dma can cause data to be copied to a stale mapping if a
copy-on-write fault occurs during dma.  The application sees missing
data.

The following trace is triggered by modifying the kernel to WARN if it
ever triggers copy-on-write on a page that is undergoing dma:

 WARNING: CPU: 24 PID: 2529 at lib/dma-debug.c:485 debug_dma_assert_idle+0xd2/0x120()
 ioatdma 0000:00:04.0: DMA-API: cpu touching an active dma mapped page [pfn=0x16bcd9]
 Modules linked in: iTCO_wdt iTCO_vendor_support ioatdma lpc_ich pcspkr dca
 CPU: 24 PID: 2529 Comm: linbug Tainted: G        W    3.13.0-rc1+ #353
  00000000000001e5 ffff88016f45f688 ffffffff81751041 ffff88017ab0ef70
  ffff88016f45f6d8 ffff88016f45f6c8 ffffffff8104ed9c ffffffff810f3646
  ffff8801768f4840 0000000000000282 ffff88016f6cca10 00007fa2bb699349
 Call Trace:
  [<ffffffff81751041>] dump_stack+0x46/0x58
  [<ffffffff8104ed9c>] warn_slowpath_common+0x8c/0xc0
  [<ffffffff810f3646>] ? ftrace_pid_func+0x26/0x30
  [<ffffffff8104ee86>] warn_slowpath_fmt+0x46/0x50
  [<ffffffff8139c062>] debug_dma_assert_idle+0xd2/0x120
  [<ffffffff81154a40>] do_wp_page+0xd0/0x790
  [<ffffffff811582ac>] handle_mm_fault+0x51c/0xde0
  [<ffffffff813830b9>] ? copy_user_enhanced_fast_string+0x9/0x20
  [<ffffffff8175fc2c>] __do_page_fault+0x19c/0x530
  [<ffffffff8175c196>] ? _raw_spin_lock_bh+0x16/0x40
  [<ffffffff810f3539>] ? trace_clock_local+0x9/0x10
  [<ffffffff810fa1f4>] ? rb_reserve_next_event+0x64/0x310
  [<ffffffffa0014c00>] ? ioat2_dma_prep_memcpy_lock+0x60/0x130 [ioatdma]
  [<ffffffff8175ffce>] do_page_fault+0xe/0x10
  [<ffffffff8175c862>] page_fault+0x22/0x30
  [<ffffffff81643991>] ? __kfree_skb+0x51/0xd0
  [<ffffffff813830b9>] ? copy_user_enhanced_fast_string+0x9/0x20
  [<ffffffff81388ea2>] ? memcpy_toiovec+0x52/0xa0
  [<ffffffff8164770f>] skb_copy_datagram_iovec+0x5f/0x2a0
  [<ffffffff8169d0f4>] tcp_rcv_established+0x674/0x7f0
  [<ffffffff816a68c5>] tcp_v4_do_rcv+0x2e5/0x4a0
  [..]
 ---[ end trace e30e3b01191b7617 ]---
 Mapped at:
  [<ffffffff8139c169>] debug_dma_map_page+0xb9/0x160
  [<ffffffff8142bf47>] dma_async_memcpy_pg_to_pg+0x127/0x210
  [<ffffffff8142cce9>] dma_memcpy_pg_to_iovec+0x119/0x1f0
  [<ffffffff81669d3c>] dma_skb_copy_datagram_iovec+0x11c/0x2b0
  [<ffffffff8169d1ca>] tcp_rcv_established+0x74a/0x7f0:

...the problem is that the receive path falls back to cpu-copy in
several locations and this trace is just one of the areas.  A few
options were considered to fix this:

1/ sync all dma whenever a cpu copy branch is taken

2/ modify the page fault handler to hold off while dma is in-flight

Option 1 adds yet more cpu overhead to an "offload" that struggles to compete
with cpu-copy.  Option 2 adds checks for behavior that is already documented as
broken when using get_user_pages().  At a minimum a debug mode is warranted to
catch and flag these violations of the dma-api vs get_user_pages().

Thanks to David for his reproducer.

Cc: <stable@vger.kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Reported-by: David Whipple <whipple@securedatainnovations.ch>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dma: pl330: ensure DMA descriptors are zero-initialised 2013-12-18T18:08:56+00:00 Will Deacon will.deacon@arm.com 2013-12-02T18:01:30+00:00 0baf8f6a2ac86c2c40ed0cacab8ea3d17371a1bb I see the following splat with 3.13-rc1 when attempting to perform DMA: [ 253.004516] Alignment trap: not handling instruction e1902f9f at [<c0204b40>] [ 253.004583] Unhandled fault: alignment exception (0x221) at 0xdfdfdfd7 [ 253.004646] Internal error: : 221 [#1] PREEMPT SMP ARM [ 253.004691] Modules linked in: dmatest(+) [last unloaded: dmatest] [ 253.004798] CPU: 0 PID: 671 Comm: kthreadd Not tainted 3.13.0-rc1+ #2 [ 253.004864] task: df9b0900 ti: df03e000 task.ti: df03e000 [ 253.004937] PC is at dmaengine_unmap_put+0x14/0x34 [ 253.005010] LR is at pl330_tasklet+0x3c8/0x550 [ 253.005087] pc : [<c0204b44>] lr : [<c0207478>] psr: a00e0193 [ 253.005087] sp : df03fe48 ip : 00000000 fp : df03bf18 [ 253.005178] r10: bf00e108 r9 : 00000001 r8 : 00000000 [ 253.005245] r7 : df837040 r6 : dfb41800 r5 : df837048 r4 : df837000 [ 253.005316] r3 : dfdfdfcf r2 : dfb41f80 r1 : df837048 r0 : dfdfdfd7 [ 253.005384] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 253.005459] Control: 30c5387d Table: 9fb9ba80 DAC: fffffffd [ 253.005520] Process kthreadd (pid: 671, stack limit = 0xdf03e248) This is due to desc->txd.unmap containing garbage (uninitialised memory). Rather than add another dummy initialisation to _init_desc, instead ensure that the descriptors are zero-initialised during allocation and remove the dummy, per-field initialisation. Cc: Andriy Shevchenko <andriy.shevchenko@intel.com> Acked-by: Jassi Brar <jassisinghbrar@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
I see the following splat with 3.13-rc1 when attempting to perform DMA:

[  253.004516] Alignment trap: not handling instruction e1902f9f at [<c0204b40>]
[  253.004583] Unhandled fault: alignment exception (0x221) at 0xdfdfdfd7
[  253.004646] Internal error: : 221 [#1] PREEMPT SMP ARM
[  253.004691] Modules linked in: dmatest(+) [last unloaded: dmatest]
[  253.004798] CPU: 0 PID: 671 Comm: kthreadd Not tainted 3.13.0-rc1+ #2
[  253.004864] task: df9b0900 ti: df03e000 task.ti: df03e000
[  253.004937] PC is at dmaengine_unmap_put+0x14/0x34
[  253.005010] LR is at pl330_tasklet+0x3c8/0x550
[  253.005087] pc : [<c0204b44>]    lr : [<c0207478>]    psr: a00e0193
[  253.005087] sp : df03fe48  ip : 00000000  fp : df03bf18
[  253.005178] r10: bf00e108  r9 : 00000001  r8 : 00000000
[  253.005245] r7 : df837040  r6 : dfb41800  r5 : df837048  r4 : df837000
[  253.005316] r3 : dfdfdfcf  r2 : dfb41f80  r1 : df837048  r0 : dfdfdfd7
[  253.005384] Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[  253.005459] Control: 30c5387d  Table: 9fb9ba80  DAC: fffffffd
[  253.005520] Process kthreadd (pid: 671, stack limit = 0xdf03e248)

This is due to desc->txd.unmap containing garbage (uninitialised memory).

Rather than add another dummy initialisation to _init_desc, instead
ensure that the descriptors are zero-initialised during allocation and
remove the dummy, per-field initialisation.

Cc: Andriy Shevchenko <andriy.shevchenko@intel.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dmaengine: fix sleep in atomic 2013-12-13T08:57:03+00:00 Dan Williams dan.j.williams@intel.com 2013-12-13T08:57:03+00:00 8194ee27764b1a86fa7a6b0d411f0a225a6abd5f BUG: sleeping function called from invalid context at mm/mempool.c:203 in_atomic(): 1, irqs_disabled(): 0, pid: 43502, name: linbug no locks held by linbug/43502. CPU: 7 PID: 43502 Comm: linbug Not tainted 3.13.0-rc1+ #15 Hardware name: 0000000000000010 ffff88005ebd1878 ffffffff8172d512 ffff8801752bc1c0 ffff8801752bc1c0 ffff88005ebd1898 ffffffff8109d1f6 ffff88005f9a3c58 ffff880177f0f080 ffff88005ebd1918 ffffffff81161f43 ffff88005ebd18f8 Call Trace: [<ffffffff8172d512>] dump_stack+0x4e/0x68 [<ffffffff8109d1f6>] __might_sleep+0xe6/0x120 [<ffffffff81161f43>] mempool_alloc+0x93/0x170 [<ffffffff810c0c34>] ? mark_held_locks+0x74/0x140 [<ffffffff8118a826>] ? follow_page_mask+0x556/0x600 [<ffffffff814107ae>] dmaengine_get_unmap_data+0x2e/0x60 [<ffffffff81410f11>] dma_async_memcpy_pg_to_pg+0x41/0x1c0 [<ffffffff814110e0>] dma_async_memcpy_buf_to_pg+0x50/0x60 [<ffffffff81411bdc>] dma_memcpy_to_iovec+0xfc/0x190 [<ffffffff816163af>] dma_skb_copy_datagram_iovec+0x6f/0x2b0 Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
 BUG: sleeping function called from invalid context at mm/mempool.c:203
 in_atomic(): 1, irqs_disabled(): 0, pid: 43502, name: linbug
 no locks held by linbug/43502.
 CPU: 7 PID: 43502 Comm: linbug Not tainted 3.13.0-rc1+ #15
 Hardware name:
  0000000000000010 ffff88005ebd1878 ffffffff8172d512 ffff8801752bc1c0
  ffff8801752bc1c0 ffff88005ebd1898 ffffffff8109d1f6 ffff88005f9a3c58
  ffff880177f0f080 ffff88005ebd1918 ffffffff81161f43 ffff88005ebd18f8
 Call Trace:
  [<ffffffff8172d512>] dump_stack+0x4e/0x68
  [<ffffffff8109d1f6>] __might_sleep+0xe6/0x120
  [<ffffffff81161f43>] mempool_alloc+0x93/0x170
  [<ffffffff810c0c34>] ? mark_held_locks+0x74/0x140
  [<ffffffff8118a826>] ? follow_page_mask+0x556/0x600
  [<ffffffff814107ae>] dmaengine_get_unmap_data+0x2e/0x60
  [<ffffffff81410f11>] dma_async_memcpy_pg_to_pg+0x41/0x1c0
  [<ffffffff814110e0>] dma_async_memcpy_buf_to_pg+0x50/0x60
  [<ffffffff81411bdc>] dma_memcpy_to_iovec+0xfc/0x190
  [<ffffffff816163af>] dma_skb_copy_datagram_iovec+0x6f/0x2b0

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dmaengine: mv_xor: fix oops when channels fail to initialise 2013-12-13T06:48:53+00:00 Russell King rmk+kernel@arm.linux.org.uk 2013-12-12T23:59:08+00:00 0be8253fa2b4385e6246387db1d6067366e987ba When a channel fails to initialise, we error out and clean up any previously unregistered channels by walking the entire xordev->channels array. Unfortunately, there are paths which end up storing an error pointer in this array, which we then try and dereference in the cleanup code, which causes an oops. Fix this by avoiding writing invalid pointers to this array in the first place. Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
When a channel fails to initialise, we error out and clean up any
previously unregistered channels by walking the entire xordev->channels
array.  Unfortunately, there are paths which end up storing an error
pointer in this array, which we then try and dereference in the cleanup
code, which causes an oops.

Fix this by avoiding writing invalid pointers to this array in the first
place.

Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dma: mv_xor: Use dmaengine_unmap_data for the self-tests 2013-12-13T06:48:53+00:00 Ezequiel Garcia ezequiel.garcia@free-electrons.com 2013-12-10T12:32:36+00:00 d16695a75019ac4baad7a117dc86d1d292e09115 The driver-specific unmap code was removed in: commit 54f8d501e842879143e867e70996574a54d1e130 Author: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Date: Fri Oct 18 19:35:32 2013 +0200 dmaengine: remove DMA unmap from drivers which had the side-effect of not unmapping the self-test mappings. Fix this by using dmaengine_unmap_data in the self-test routines. In addition, since dmaengine_unmap() assumes that all mappings were created with dma_map_page, this commit changes the single mapping to a page mapping to avoid an incorrect unmapping of the memcpy self-test. The allocation could be changed to be alloc_page(), but sticking to kmalloc results in a less intrusive patch. The size of the test buffer is increased, since dma_map_page() seem to fail when the source and destination pages are the same page. Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
The driver-specific unmap code was removed in:

  commit 54f8d501e842879143e867e70996574a54d1e130
  Author: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
  Date:   Fri Oct 18 19:35:32 2013 +0200

      dmaengine: remove DMA unmap from drivers

which had the side-effect of not unmapping the self-test mappings.
Fix this by using dmaengine_unmap_data in the self-test routines.

In addition, since dmaengine_unmap() assumes that all mappings were created
with dma_map_page, this commit changes the single mapping to a page mapping
to avoid an incorrect unmapping of the memcpy self-test.

The allocation could be changed to be alloc_page(), but sticking to kmalloc
results in a less intrusive patch. The size of the test buffer is increased,
since dma_map_page() seem to fail when the source and destination pages are
the same page.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dmaengine: fix enable for high order unmap pools 2013-12-13T06:43:42+00:00 Dan Williams dan.j.williams@intel.com 2013-12-09T18:33:16+00:00 3cc377b9ae4bd3133bf8ba388d2b2b66b2b973c1 The higher order mempools support raid operations, and we want to disable them when raid support is not enabled. Making them conditional on ASYNC_TX_DMA is not sufficient as other users (specifically dmatest) will also issue raid operations. Make raid drivers explicitly request that the core carry the higher order pools. Reported-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
The higher order mempools support raid operations, and we want to
disable them when raid support is not enabled.  Making them conditional
on ASYNC_TX_DMA is not sufficient as other users (specifically dmatest)
will also issue raid operations.  Make raid drivers explicitly request
that the core carry the higher order pools.

Reported-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dma: fix build warnings in txx9 2013-12-13T06:43:41+00:00 Dan Williams dan.j.williams@intel.com 2013-12-09T19:16:03+00:00 8e5ee258d98a6643227d958361aec2a62559b804 The unmap rework missed this: drivers/dma/txx9dmac.c:409:25: warning: unused variable 'ds' [-Wunused-variable] Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
The unmap rework missed this:
drivers/dma/txx9dmac.c:409:25: warning: unused variable 'ds' [-Wunused-variable]

Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dmatest: fix build warning on mips 2013-12-13T06:43:41+00:00 Dan Williams dan.j.williams@intel.com 2013-12-09T19:16:01+00:00 745c00daf9a75bacb53d0fe8635a132673ab0b46 drivers/dma/dmatest.c:543:11: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default] mips expects virt_to_phys() to take a pointer. Fix up the types accordingly. Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
drivers/dma/dmatest.c:543:11: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]

mips expects virt_to_phys() to take a pointer.  Fix up the types accordingly.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dma: fix fsldma build warnings 2013-12-13T06:43:41+00:00 Dan Williams dan.j.williams@intel.com 2013-12-09T19:16:00+00:00 bbc76560d488c437dbddff72242b0a07e42a0fd0 drivers/dma/fsldma.c: In function 'fsldma_cleanup_descriptor': drivers/dma/fsldma.c:860:6: warning: unused variable 'len' [-Wunused-variable] drivers/dma/fsldma.c:859:13: warning: unused variable 'dst' [-Wunused-variable] drivers/dma/fsldma.c:858:13: warning: unused variable 'src' [-Wunused-variable] drivers/dma/fsldma.c:857:17: warning: unused variable 'dev' [-Wunused-variable] - due to unmap changes drivers/dma/fsldma.c: In function 'fsl_dma_tx_submit': drivers/dma/fsldma.c:428:2: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized] - long standing warning Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Li Yang <leoli@freescale.com> Cc: Zhang Wei <zw@zh-kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
drivers/dma/fsldma.c: In function 'fsldma_cleanup_descriptor':
drivers/dma/fsldma.c:860:6: warning: unused variable 'len' [-Wunused-variable]
drivers/dma/fsldma.c:859:13: warning: unused variable 'dst' [-Wunused-variable]
drivers/dma/fsldma.c:858:13: warning: unused variable 'src' [-Wunused-variable]
drivers/dma/fsldma.c:857:17: warning: unused variable 'dev' [-Wunused-variable]
- due to unmap changes

drivers/dma/fsldma.c: In function 'fsl_dma_tx_submit':
drivers/dma/fsldma.c:428:2: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized]
- long standing warning

Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Zhang Wei <zw@zh-kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dma: fix build warnings in ppc4xx 2013-12-13T06:43:41+00:00 Dan Williams dan.j.williams@intel.com 2013-12-09T19:15:59+00:00 6aa2731ce2c7bd1305b553b5fc14ae4856d36569 drivers/dma/ppc4xx/adma.c:1507:6: warning: unused variable 'i' [-Wunused-variable] - due to unmap reworks drivers/dma/ppc4xx/adma.c:3900:2: warning: format '%s' expects a matching 'char *' argument [-Wformat] - due to memset removal drivers/dma/ppc4xx/adma.c:538:13: warning: 'ppc440spe_desc_init_memset' defined but not used [-Wunused-function] - due to memset removal Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
drivers/dma/ppc4xx/adma.c:1507:6: warning: unused variable 'i' [-Wunused-variable]
- due to unmap reworks

drivers/dma/ppc4xx/adma.c:3900:2: warning: format '%s' expects a matching 'char *' argument [-Wformat]
- due to memset removal

drivers/dma/ppc4xx/adma.c:538:13: warning: 'ppc440spe_desc_init_memset' defined but not used [-Wunused-function]
- due to memset removal

Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>