There is a DMA problem with the serial ports on i.MX6.
When the following sequence is performed:
1) Open a port
2) Write some data
3) Close the port
4) Open a *different* port
5) Write some data
6) Close the port
The second write sends nothing and the second close hangs.
If the first close() is omitted it works.
Adding logs to the the UART driver shows that the DMA is being setup but
the callback is never invoked for the second write.
This used to work in 4.19.
Git bisect leads to:
ad0d92d: "dmaengine: imx-sdma: refine to load context only once"
This commit adds a "context_loaded" flag used to avoid unnecessary context
setups.
However the flag is only reset in sdma_channel_terminate_work(),
which is only invoked in a worker triggered by sdma_terminate_all() IF
there is an active descriptor.
So, if no active descriptor remains when the channel is terminated, the
flag is not reset and, when the channel is later reused the old context
is used.
Fix the problem by always resetting the flag in sdma_free_chan_resources().
Cc: stable@vger.kernel.org
Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Fixes: ad0d92d7ba ("dmaengine: imx-sdma: refine to load context only once")
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/1580305274-27274-1-git-send-email-martin.fuzzey@flowbird.group
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reset DMA channel after stop to ensure that pending transfers and FIFOs
in the datapath are flushed or completed. It also cleanup the terminate
path and removes stop for the cyclic mode as after the reset stop is not
required. This fixes intermittent data verification failure when xilinx
dma test the client is stressed and loaded/unloaded multiple times.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1580283909-32678-1-git-send-email-radhey.shyam.pandey@xilinx.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200214171302.GA20586@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200214171657.GA25663@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/20200214171536.GA24077@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200214171435.GA22930@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When we receive back the descriptor of the terminated transfer the cookie
must be marked as completed to make sure that the accounting is correct.
In udma_tx_status() the status should be marked as completed if the channel
is no longer running (it can only happen if the channel is not yet started
for the first time, or after a channel termination).
Fixes: 25dcb5dd7b ("dmaengine: ti: New driver for K3 UDMA")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200214091441.27535-7-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
It should be possible to pause, resume and check the pause state of a
channel even if we do not have active transfer.
udma_is_chan_paused() can trigger NULL pointer reference in it's current
form when the status is checked while uc->desc is NULL.
Fixes: 25dcb5dd7b ("dmaengine: ti: New driver for K3 UDMA")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200214091441.27535-6-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Use the generic TR setup function to get the TR counters for both cyclic
and slave_sg transfers.
This way the period_size for cyclic and sg_dma_len() for slave_sg can be
as large as (SZ_64K - 1) * (SZ_64K - 1) and we can handle cases when the
length is >SZ_64K and a prime number.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200214091441.27535-5-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When a channel is asked to be stopped (teardown) and we do not have active
descriptor to receive stale data buffered on the remote side then the
teardown will not complete as UDMA needs a descriptor to be able to flush
out the DMA pipe.
The peer is trying to push the data to UDMA in teardown, but UDMA is
pushing back because it has no descriptor which would allow it to drain the
data.
The workaround is to create 1K 'trashcan' to receive the discarded data and
set up descriptors for packet and TR mode channels.
When a channel is stopped and there is no active descriptor then a
descriptor is pushed to the ring for UDMA before the teardown is initiated.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200214091441.27535-3-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drivers/dma/sun4i-dma.c: In function sun4i_dma_prep_dma_cyclic:
drivers/dma/sun4i-dma.c:672:24: warning:
variable linear_mode set but not used [-Wunused-but-set-variable]
commit ffc079a4ac ("dmaengine: sun4i: Add support for cyclic requests with dedicated DMA")
involved this, explicitly using the value makes the code more readable.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200207024445.44600-1-yuehaibing@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200213003925.GA6906@embeddedor.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200213003535.GA3269@embeddedor.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200213003703.GA4177@embeddedor.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
No need to use goto to jump over the
return chan ? chan : ERR_PTR(-EPROBE_DEFER);
We can just revert the check and return right there.
Do not fail the channel request if the chan->name allocation fails, but
print a warning about it.
Change the dev_err to dev_warn if sysfs_create_link() fails as it is not
fatal.
Only attempt to remove the DMA_SLAVE_NAME symlink if it is created - or it
was attempted to be created.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200131093859.3311-2-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Commit 71723a96b8 ("dmaengine: Create symlinks between DMA channels and
slaves") changed the dma_request_chan() function flow in such a way that
it always returns EPROBE_DEFER in case of channels that cannot be found.
This break the operation of the devices which have optional DMA channels
as it puts their drivers in endless deferred probe loop. Fix this by
propagating the proper error value.
Fixes: 71723a96b8 ("dmaengine: Create symlinks between DMA channels and slaves")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200130070834.17537-1-m.szyprowski@samsung.com
[vkoul: fix typo in patch title]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull ioremap updates from Christoph Hellwig:
"Remove the ioremap_nocache API (plus wrappers) that are always
identical to ioremap"
* tag 'ioremap-5.6' of git://git.infradead.org/users/hch/ioremap:
remove ioremap_nocache and devm_ioremap_nocache
MIPS: define ioremap_nocache to ioremap
Pull dmaengine updates from Vinod Koul:
"This time we have a bunch of core changes to support dynamic channels,
hotplug of controllers, new apis for metadata ops etc along with new
drivers for Intel data accelerators, TI K3 UDMA, PLX DMA engine and
hisilicon Kunpeng DMA engine. Also usual assorted updates to drivers.
Core:
- Support for dynamic channels
- Removal of various slave wrappers
- Make few slave request APIs as private to dmaengine
- Symlinks between channels and slaves
- Support for hotplug of controllers
- Support for metadata_ops for dma_async_tx_descriptor
- Reporting DMA cached data amount
- Virtual dma channel locking updates
New drivers/device/feature support support:
- Driver for Intel data accelerators
- Driver for TI K3 UDMA
- Driver for PLX DMA engine
- Driver for hisilicon Kunpeng DMA engine
- Support for eDMA support for QorIQ LS1028A in fsl edma driver
- Support for cyclic dma in sun4i driver
- Support for X1830 in JZ4780 driver"
* tag 'dmaengine-5.6-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (62 commits)
dmaengine: Create symlinks between DMA channels and slaves
dmaengine: hisilicon: Add Kunpeng DMA engine support
dmaengine: idxd: add char driver to expose submission portal to userland
dmaengine: idxd: connect idxd to dmaengine subsystem
dmaengine: idxd: add descriptor manipulation routines
dmaengine: idxd: add sysfs ABI for idxd driver
dmaengine: idxd: add configuration component of driver
dmaengine: idxd: Init and probe for Intel data accelerators
dmaengine: add support to dynamic register/unregister of channels
dmaengine: break out channel registration
x86/asm: add iosubmit_cmds512() based on MOVDIR64B CPU instruction
dmaengine: ti: k3-udma: fix spelling mistake "limted" -> "limited"
dmaengine: s3c24xx-dma: fix spelling mistake "to" -> "too"
dmaengine: Move dma_get_{,any_}slave_channel() to private dmaengine.h
dmaengine: Remove dma_request_slave_channel_compat() wrapper
dmaengine: Remove dma_device_satisfies_mask() wrapper
dt-bindings: fsl-imx-sdma: Add i.MX8MM/i.MX8MN/i.MX8MP compatible string
dmaengine: zynqmp_dma: fix burst length configuration
dmaengine: sun4i: Add support for cyclic requests with dedicated DMA
dmaengine: fsl-qdma: fix duplicated argument to &&
...
Currently it is not easy to find out which DMA channels are in use, and
which slave devices are using which channels.
Fix this by creating two symlinks between the DMA channel and the actual
slave device when a channel is requested:
1. A "slave" symlink from DMA channel to slave device,
2. A "dma:<name>" symlink slave device to DMA channel.
When the channel is released, the symlinks are removed again.
The latter requires keeping track of the slave device and the channel
name in the dma_chan structure.
Note that this is limited to channel request functions for requesting an
exclusive slave channel that take a device pointer (dma_request_chan()
and dma_request_slave_channel*()).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Link: https://lore.kernel.org/r/20200117153056.31363-1-geert+renesas@glider.be
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Create a char device region that will allow acquisition of user portals in
order to allow applications to submit DMA operations. A char device will be
created per work queue that gets exposed. The workqueue type "user"
is used to mark a work queue for user char device. For example if the
workqueue 0 of DSA device 0 is marked for char device, then a device node
of /dev/dsa/wq0.0 will be created.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965026985.73301.976523230037106742.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
