linux-stable.git/drivers/dma, branch v4.4.192

dmaengine: ste_dma40: fix unneeded variable warning

2019-09-06T08:18:14+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

2019-08-06T16:28:26+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: imx-sdma: fix use-after-free on probe error path

2019-08-04T07:34:37+00:00

[ Upstream commit 2b8066c3deb9140fdf258417a51479b2aeaa7622 ]

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 
Signed-off-by: Sasha Levin

dmaengine: imx-sdma: remove BD_INTR for channel0

2019-07-10T07:56:44+00:00

commit 3f93a4f297961c12bb17aa16cb3a4d1291823cae upstream.

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 
Signed-off-by: Greg Kroah-Hartman

dmaengine: idma64: Use actual device for DMA transfers

2019-06-22T06:18:21+00:00

[ Upstream commit 5ba846b1ee0792f5a596b9b0b86d6e8cdebfab06 ]

Intel IOMMU, when enabled, tries to find the domain of the device,
assuming it's a PCI one, during DMA operations, such as mapping or
unmapping. Since we are splitting the actual PCI device to couple of
children via MFD framework (see drivers/mfd/intel-lpss.c for details),
the DMA device appears to be a platform one, and thus not an actual one
that performs DMA. In a such situation IOMMU can't find or allocate
a proper domain for its operations. As a result, all DMA operations are
failed.

In order to fix this, supply parent of the platform device
to the DMA engine framework and fix filter functions accordingly.

We may rely on the fact that parent is a real PCI device, because no
other configuration is present in the wild.

Signed-off-by: Andy Shevchenko 
Acked-by: Mark Brown 
Acked-by: Greg Kroah-Hartman  [for tty parts]
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: at_xdmac: remove BUG_ON macro in tasklet

2019-06-11T10:23:57+00:00

[ Upstream commit e2c114c06da2d9ffad5b16690abf008d6696f689 ]

Even if this case shouldn't happen when controller is properly programmed,
it's still better to avoid dumping a kernel Oops for this.
As the sequence may happen only for debugging purposes, log the error and
just finish the tasklet call.

Signed-off-by: Nicolas Ferre 
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: pl330: _stop: clear interrupt status

2019-06-11T10:23:55+00:00

[ Upstream commit 2da254cc7908105a60a6bb219d18e8dced03dcb9 ]

This patch kill instructs the DMAC to immediately terminate
execution of a thread. and then clear the interrupt status,
at last, stop generating interrupts for DMA_SEV. to guarantee
the next dma start is clean. otherwise, one interrupt maybe leave
to next start and make some mistake.

we can reporduce the problem as follows:

DMASEV: modify the event-interrupt resource, and if the INTEN sets
function as interrupt, the DMAC will set irq HIGH to
generate interrupt. write INTCLR to clear interrupt.

	DMA EXECUTING INSTRUCTS		DMA TERMINATE
		|				|
		|				|
	       ...			      _stop
		|				|
		|			spin_lock_irqsave
	     DMASEV				|
		|				|
		|			    mask INTEN
		|				|
		|			     DMAKILL
		|				|
		|			spin_unlock_irqrestore

in above case, a interrupt was left, and if we unmask INTEN, the DMAC
will set irq HIGH to generate interrupt.

to fix this, do as follows:

	DMA EXECUTING INSTRUCTS		DMA TERMINATE
		|				|
		|				|
	       ...			      _stop
		|				|
		|			spin_lock_irqsave
	     DMASEV				|
		|				|
		|			     DMAKILL
		|				|
		|			   clear INTCLR
		|			    mask INTEN
		|				|
		|			spin_unlock_irqrestore

Signed-off-by: Sugar Zhang 
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: tegra: avoid overflow of byte tracking

2019-04-27T07:33:53+00:00

[ Upstream commit e486df39305864604b7e25f2a95d51039517ac57 ]

The dma_desc->bytes_transferred counter tracks the number of bytes
moved by the DMA channel. This is then used to calculate the information
passed back in the in the tegra_dma_tx_status callback, which is usually
fine.

When the DMA channel is configured as continous, then the bytes_transferred
counter will increase over time and eventually overflow to become negative
so the residue count will become invalid and the ALSA sound-dma code will
report invalid hardware pointer values to the application. This results in
some users becoming confused about the playout position and putting audio
data in the wrong place.

To fix this issue, always ensure the bytes_transferred field is modulo the
size of the request. We only do this for the case of the cyclic transfer
done ISR as anyone attempting to move 2GiB of DMA data in one transfer
is unlikely.

Note, we don't fix the issue that we should /never/ transfer a negative
number of bytes so we could make those fields unsigned.

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

dmaengine: imx-dma: fix warning comparison of distinct pointer types

2019-04-27T07:33:52+00:00

[ Upstream commit 9227ab5643cb8350449502dd9e3168a873ab0e3b ]

The warning got introduced by commit 930507c18304 ("arm64: add basic
Kconfig symbols for i.MX8"). Since it got enabled for arm64. The warning
haven't been seen before since size_t was 'unsigned int' when built on
arm32.

../drivers/dma/imx-dma.c: In function ‘imxdma_sg_next’:
../include/linux/kernel.h:846:29: warning: comparison of distinct pointer types lacks a cast
   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                             ^~
../include/linux/kernel.h:860:4: note: in expansion of macro ‘__typecheck’
   (__typecheck(x, y) && __no_side_effects(x, y))
    ^~~~~~~~~~~
../include/linux/kernel.h:870:24: note: in expansion of macro ‘__safe_cmp’
  __builtin_choose_expr(__safe_cmp(x, y), \
                        ^~~~~~~~~~
../include/linux/kernel.h:879:19: note: in expansion of macro ‘__careful_cmp’
 #define min(x, y) __careful_cmp(x, y, <)
                   ^~~~~~~~~~~~~
../drivers/dma/imx-dma.c:288:8: note: in expansion of macro ‘min’
  now = min(d->len, sg_dma_len(sg));
        ^~~

Rework so that we use min_t and pass in the size_t that returns the
minimum of two values, using the specified type.

Signed-off-by: Anders Roxell 
Acked-by: Olof Johansson 
Reviewed-by: Fabio Estevam 
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: usb-dmac: Make DMAC system sleep callbacks explicit

2019-03-23T07:44:36+00:00

commit d9140a0da4a230a03426d175145989667758aa6a upstream.

This commit fixes the issue that USB-DMAC hangs silently after system
resumes on R-Car Gen3 hence renesas_usbhs will not work correctly
when using USB-DMAC for bulk transfer e.g. ethernet or serial
gadgets.

The issue can be reproduced by these steps:
 1. modprobe g_serial
 2. Suspend and resume system.
 3. connect a usb cable to host side
 4. Transfer data from Host to Target
 5. cat /dev/ttyGS0 (Target side)
 6. echo "test" > /dev/ttyACM0 (Host side)

The 'cat' will not result anything. However, system still can work
normally.

Currently, USB-DMAC driver does not have system sleep callbacks hence
this driver relies on the PM core to force runtime suspend/resume to
suspend and reinitialize USB-DMAC during system resume. After
the commit 17218e0092f8 ("PM / genpd: Stop/start devices without
pm_runtime_force_suspend/resume()"), PM core will not force
runtime suspend/resume anymore so this issue happens.

To solve this, make system suspend resume explicit by using
pm_runtime_force_{suspend,resume}() as the system sleep callbacks.
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS() is used to make sure USB-DMAC
suspended after and initialized before renesas_usbhs."

Signed-off-by: Phuong Nguyen 
Signed-off-by: Hiroyuki Yokoyama 
Cc:  # v4.16+
[shimoda: revise the commit log and add Cc tag]
Signed-off-by: Yoshihiro Shimoda 
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman