linux-stable.git/drivers/dma, branch v5.2.16

omap-dma/omap_vout_vrfb: fix off-by-one fi value

2019-09-06T08:23:18+00:00

[ Upstream commit d555c34338cae844b207564c482e5a3fb089d25e ]

The OMAP 4 TRM specifies that when using double-index addressing
the address increases by the ES plus the EI value minus 1 within
a frame. When a full frame is transferred, the address increases
by the ES plus the frame index (FI) value minus 1.

The omap-dma code didn't account for the 'minus 1' in the FI register.
To get correct addressing, add 1 to the src_icg value.

This was found when testing a hacked version of the media m2m-deinterlace.c
driver on a Pandaboard.

The only other source that uses this feature is omap_vout_vrfb.c,
and that adds a + 1 when setting the dst_icg. This is a workaround
for the broken omap-dma.c behavior. So remove the workaround at the
same time that we fix omap-dma.c.

I tested the omap_vout driver with a Beagle XM board to check that
the '+ 1' in omap_vout_vrfb.c was indeed a workaround for the omap-dma
bug.

Signed-off-by: Hans Verkuil 
Reviewed-by: Laurent Pinchart 
Acked-by: Peter Ujfalusi 
Acked-by: Mauro Carvalho Chehab 
Link: https://lore.kernel.org/r/952e7f51-f208-9333-6f58-b7ed20d2ea0b@xs4all.nl
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: stm32-mdma: Fix a possible null-pointer dereference in stm32_mdma_irq_handler()

2019-09-06T08:23:18+00:00

[ Upstream commit 39c71a5b8212f4b502d9a630c6706ac723abd422 ]

In stm32_mdma_irq_handler(), chan is checked on line 1368.
When chan is NULL, it is still used on line 1369:
    dev_err(chan2dev(chan), "MDMA channel not initialized\n");

Thus, a possible null-pointer dereference may occur.

To fix this bug, "dev_dbg(mdma2dev(dmadev), ...)" is used instead.

Signed-off-by: Jia-Ju Bai 
Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver")
Link: https://lore.kernel.org/r/20190729020849.17971-1-baijiaju1990@gmail.com
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: ste_dma40: fix unneeded variable warning

2019-09-06T08:23:13+00:00

[ Upstream commit 5d6fb560729a5d5554e23db8d00eb57cd0021083 ]

clang-9 points out that there are two variables that depending on the
configuration may only be used in an ARRAY_SIZE() expression but not
referenced:

drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration]
static u32 d40_backup_regs[] = {
           ^
drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration]
static u32 d40_backup_regs_chan[] = {

Mark these __maybe_unused to shut up the warning.

Signed-off-by: Arnd Bergmann 
Reviewed-by: Nathan Chancellor 
Reviewed-by: Linus Walleij 
Link: https://lore.kernel.org/r/20190712091357.744515-1-arnd@arndb.de
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: rcar-dmac: Reject zero-length slave DMA requests

2019-08-06T17:08:05+00:00

[ Upstream commit 78efb76ab4dfb8f74f290ae743f34162cd627f19 ]

While the .device_prep_slave_sg() callback rejects empty scatterlists,
it still accepts single-entry scatterlists with a zero-length segment.
These may happen if a driver calls dmaengine_prep_slave_single() with a
zero len parameter.  The corresponding DMA request will never complete,
leading to messages like:

    rcar-dmac e7300000.dma-controller: Channel Address Error happen

and DMA timeouts.

Although requesting a zero-length DMA request is a driver bug, rejecting
it early eases debugging.  Note that the .device_prep_dma_memcpy()
callback already rejects requests to copy zero bytes.

Reported-by: Eugeniu Rosca 
Analyzed-by: Yoshihiro Shimoda 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: tegra-apb: Error out if DMA_PREP_INTERRUPT flag is unset

2019-08-06T17:08:04+00:00

[ Upstream commit dc161064beb83c668e0f85766b92b1e7ed186e58 ]

Apparently driver was never tested with DMA_PREP_INTERRUPT flag being
unset since it completely disables interrupt handling instead of skipping
the callbacks invocations, hence putting channel into unusable state.

The flag is always set by all of kernel drivers that use APB DMA, so let's
error out in otherwise case for consistency. It won't be difficult to
support that case properly if ever will be needed.

Signed-off-by: Dmitry Osipenko 
Acked-by: Jon Hunter 
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

Merge tag 'dmaengine-fix-5.2' of git://git.infradead.org/users/vkoul/slave-dma

2019-07-06T17:06:37+00:00

Pull dmaengine fixes from Vinod Koul:

 - bam_dma fix for completed descriptor count

 - fix for imx-sdma remove BD_INTR for channel0 and use-after-free on
   probe error path

 - endian bug fix in jz4780 IRQ handler

* tag 'dmaengine-fix-5.2' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: qcom: bam_dma: Fix completed descriptors count
  dmaengine: imx-sdma: remove BD_INTR for channel0
  dmaengine: imx-sdma: fix use-after-free on probe error path
  dmaengine: jz4780: Fix an endian bug in IRQ handler

dmaengine: qcom: bam_dma: Fix completed descriptors count

2019-07-05T07:48:27+00:00

One space is left unused in circular FIFO to differentiate
'full' and 'empty' cases. So take that in to account while
counting for the descriptors completed.

Fixes the issue reported here,
	https://lkml.org/lkml/2019/6/18/669

Cc: stable@vger.kernel.org
Reported-by: Srinivas Kandagatla 
Signed-off-by: Sricharan R 
Tested-by: Srinivas Kandagatla 
Signed-off-by: Vinod Koul

dmaengine: imx-sdma: remove BD_INTR for channel0

2019-07-05T07:45:37+00:00

It is possible for an irq triggered by channel0 to be received later
after clks are disabled once firmware loaded during sdma probe. If
that happens then clearing them by writing to SDMA_H_INTR won't work
and the kernel will hang processing infinite interrupts. Actually,
don't need interrupt triggered on channel0 since it's pollling
SDMA_H_STATSTOP to know channel0 done rather than interrupt in
current code, just clear BD_INTR to disable channel0 interrupt to
avoid the above case.
This issue was brought by commit 1d069bfa3c78 ("dmaengine: imx-sdma:
ack channel 0 IRQ in the interrupt handler") which didn't take care
the above case.

Fixes: 1d069bfa3c78 ("dmaengine: imx-sdma: ack channel 0 IRQ in the interrupt handler")
Cc: stable@vger.kernel.org #5.0+
Signed-off-by: Robin Gong 
Reported-by: Sven Van Asbroeck 
Tested-by: Sven Van Asbroeck 
Reviewed-by: Michael Olbrich 
Signed-off-by: Vinod Koul

dmaengine: imx-sdma: fix use-after-free on probe error path

2019-07-05T07:28:54+00:00

If probe() fails anywhere beyond the point where
sdma_get_firmware() is called, then a kernel oops may occur.

Problematic sequence of events:
1. probe() calls sdma_get_firmware(), which schedules the
   firmware callback to run when firmware becomes available,
   using the sdma instance structure as the context
2. probe() encounters an error, which deallocates the
   sdma instance structure
3. firmware becomes available, firmware callback is
   called with deallocated sdma instance structure
4. use after free - kernel oops !

Solution: only attempt to load firmware when we're certain
that probe() will succeed. This guarantees that the firmware
callback's context will remain valid.

Note that the remove() path is unaffected by this issue: the
firmware loader will increment the driver module's use count,
ensuring that the module cannot be unloaded while the
firmware callback is pending or running.

Signed-off-by: Sven Van Asbroeck 
Reviewed-by: Robin Gong 
[vkoul: fixed braces for if condition]
Signed-off-by: Vinod Koul

dmaengine: jz4780: Fix an endian bug in IRQ handler

2019-07-05T07:15:56+00:00

The "pending" variable was a u32 but we cast it to an unsigned long
pointer when we do the for_each_set_bit() loop.  The problem is that on
big endian 64bit systems that results in an out of bounds read.

Fixes: 4e4106f5e942 ("dmaengine: jz4780: Fix transfers being ACKed too soon")
Signed-off-by: Dan Carpenter 
Signed-off-by: Vinod Koul