comedi_open() invokes comedi_dev_get_from_minor(), which returns a
reference of the COMEDI device to "dev" with increased refcount.
When comedi_open() returns, "dev" becomes invalid, so the refcount
should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
comedi_open(). When "cfp" allocation is failed, the refcnt increased by
comedi_dev_get_from_minor() is not decreased, causing a refcnt leak.
Fix this issue by calling comedi_dev_put() on this error path when "cfp"
allocation is failed.
Fixes: 20f083c075 ("staging: comedi: prepare support for per-file read and write subdevices")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/1587361459-83622-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DT2815 analog output command is 16 bits wide, consisting of the
12-bit sample value in bits 15 to 4, the channel number in bits 3 to 1,
and a voltage or current selector in bit 0. Both bytes of the 16-bit
command need to be written in turn to a single 8-bit data register.
However, the driver currently only writes the low 8-bits. It is broken
and appears to have always been broken.
Electronic copies of the DT2815 User's Manual seem impossible to find
online, but looking at the source code, a best guess for the sequence
the driver intended to use to write the analog output command is as
follows:
1. Wait for the status register to read 0x00.
2. Write the low byte of the command to the data register.
3. Wait for the status register to read 0x80.
4. Write the high byte of the command to the data register.
Step 4 is missing from the driver. Add step 4 to (hopefully) fix the
driver.
Also add a "FIXME" comment about setting bit 0 of the low byte of the
command. Supposedly, it is used to choose between voltage output and
current output, but the current driver always sets it to 1.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200406142015.126982-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here are 3 SPDX patches for 5.7-rc1.
One fixes up the SPDX tag for a single driver, while the other two go
through the tree and add SPDX tags for all of the .gitignore files as
needed.
Nothing too complex, but you will get a merge conflict with your current
tree, that should be trivial to handle (one file modified by two things,
one file deleted.)
All 3 of these have been in linux-next for a while, with no reported
issues other than the merge conflict.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx
Pull SPDX updates from Greg KH:
"Here are three SPDX patches for 5.7-rc1.
One fixes up the SPDX tag for a single driver, while the other two go
through the tree and add SPDX tags for all of the .gitignore files as
needed.
Nothing too complex, but you will get a merge conflict with your
current tree, that should be trivial to handle (one file modified by
two things, one file deleted.)
All three of these have been in linux-next for a while, with no
reported issues other than the merge conflict"
* tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
ASoC: MT6660: make spdxcheck.py happy
.gitignore: add SPDX License Identifier
.gitignore: remove too obvious comments
Reformat multi-line dereferencing of function arguments
&cmd->scan_begin_arg. Also reformat another call to the same function to
follow the same argument formatting structure. Problem detected by
checkpatch script.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200322185932.GA12594@deeUbuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reformat multiple line dereferences for &cmd->scan_begin_arg. Problem
detected by checkpatch.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200314135852.GA6336@deeUbuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Resolve general code indentation problems as detected by checkpatch script.
Implement code reformat and re-indentation as per coding style to
improve readability.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200314210749.GA3393@deeUbuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reformat function call arguments to comedi_check_trigger_arg_min
as per coding style guideline. Problem detected by checkpatch script.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200314213856.GA3874@deeUbuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reformat multi-line dereferencing of function arguments
&cmd->scan_begin_arg. Problem detected by checkpatch script.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200314214154.GA3904@deeUbuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reformat function call arguments so that the function call is clearly
visible. Issue detected by checkpatch.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200314214254.GA3941@deeUbuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are two #if 0 blocks that have no recent history of any change.
Remove those code blocks for improved readability of the code.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200310212545.GA8914@deeUbuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We do not currently provide routing information for NI PCIe-6251 and
PCI-6259 boards, but they are functionally identical to the PCI-6251 and
PCI-6259 boards and can share their routing information. (This has been
confirmed for the PCIe-6251 by Éric Piel, using the "NI MAX" software
for Windows. It is hoped that it applies to PCIe-6259, but has not yet
been checked due to lack of hardware.) Initialize the `alt_route_name`
member of the board information for PCIe-6251 and PCIe-6259 to allow
them to make use of the routing information provided for PCI-6251 and
PCI-6259 respectively.
Cc: Éric Piel <piel@delmic.com>
Cc: Spencer E. Olson <olsonse@umich.edu>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200207151400.272678-5-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We do not have or do not provide routing information for all supported
boards. Some of the boards for which we do not provide routing
information actually have routes that are identical to a similar board
for which we already provide routing information.
To allow boards to share identical routing information, add an
`alt_route_name` member to `struct ni_board_struct`. This will be
initialized to `NULL` for all boards except those that will use make use
of the identical routing information that has been provided for a
similar board, in which case it will name that board. Pass the
`alt_route_name` member value to `ni_assign_device_routes()` as the
`alt_board_name` parameter, which it will use if no routing information
could be found for the actual board name.
Cc: Éric Piel <piel@delmic.com>
Cc: Spencer E. Olson <olsonse@umich.edu>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200207151400.272678-4-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We do not have or provide routing information available for all
supported boards. Some of the boards for which we do not currently
provide routing information actually have identical routes to a similar
board for which we do provide routing information. To avoid having to
provide duplicate routing information, add an "alternate board name"
parameter (possibly `NULl`) to `ni_assign_device_routes()` and
`ni_find_device_routes()`. If the routing information cannot be found
for the actual board name, try finding it using the alternate board
name.
Cc: Éric Piel <piel@delmic.com>
Cc: Spencer E. Olson <olsonse@umich.edu>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200207151400.272678-3-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Split out the loops in `ni_find_valid_routes()` into separate functions:
* ni_find_route_values(device_family) to find the list of route values
for a device family (e.g "ni-mseries"); and
* ni_find_valid_routes(board_name) to find the set of valid routes for a
board name.
The functions above return `NULL` if the information is not found (as we
do not currently have the routing information available for all
supported boards).
Cc: Éric Piel <piel@delmic.com>
Cc: Spencer E. Olson <olsonse@umich.edu>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200207151400.272678-2-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a regression on setting up asynchronous commands to use
external trigger sources when board-specific routing information is
missing.
`ni_find_device_routes()` (called via `ni_assign_device_routes()`) finds
the table of register values for the device family and the set of valid
routes for the specific board. If both are found,
`tables->route_values` is set to point to the table of register values
for the device family and `tables->valid_routes` is set to point to the
list of valid routes for the specific board. If either is not found,
both `tables->route_values` and `tables->valid_routes` are left set at
their initial null values (initialized by `ni_assign_device_routes()`)
and the function returns `-ENODATA`.
Returning an error results in some routing functionality being disabled.
Unfortunately, leaving `table->route_values` set to `NULL` also breaks
the setting up of asynchronous commands that are configured to use
external trigger sources. Calls to `ni_check_trigger_arg()` or
`ni_check_trigger_arg_roffs()` while checking the asynchronous command
set-up would result in a null pointer dereference if
`table->route_values` is `NULL`. The null pointer dereference is fixed
in another patch, but it now results in failure to set up the
asynchronous command. That is a regression from the behavior prior to
commit 347e244884 ("staging: comedi: tio: implement global tio/ctr
routing") and commit 56d0b826d3 ("staging: comedi: ni_mio_common:
implement new routing for TRIG_EXT").
Change `ni_find_device_routes()` to set `tables->route_values` and/or
`tables->valid_routes` to valid information even if the other one can
only be set to `NULL` due to missing information. The function will
still return an error in that case. This should result in
`tables->valid_routes` being valid for all currently supported device
families even if the board-specific routing information is missing.
That should be enough to fix the regression on setting up asynchronous
commands to use external triggers for boards with missing routing
information.
Fixes: 347e244884 ("staging: comedi: tio: implement global tio/ctr routing")
Fixes: 56d0b826d3 ("staging: comedi: ni_mio_common: implement new routing for TRIG_EXT").
Cc: <stable@vger.kernel.org> # 4.20+
Cc: Spencer E. Olson <olsonse@umich.edu>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200114182532.132058-3-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In `ni_find_route_source()`, `tables->route_values` gets dereferenced.
However it is possible that `tables->route_values` is `NULL`, leading to
a null pointer dereference. `tables->route_values` will be `NULL` if
the call to `ni_assign_device_routes()` during board initialization
returned an error due to missing device family routing information or
missing board-specific routing information. For example, there is
currently no board-specific routing information provided for the
PCIe-6251 board and several other boards, so those are affected by this
bug.
The bug is triggered when `ni_find_route_source()` is called via
`ni_check_trigger_arg()` or `ni_check_trigger_arg_roffs()` when checking
the arguments for setting up asynchronous commands. Fix it by returning
`-EINVAL` if `tables->route_values` is `NULL`.
Even with this fix, setting up asynchronous commands to use external
trigger sources for boards with missing routing information will still
fail gracefully. Since `ni_find_route_source()` only depends on the
device family routing information, it would be better if that was made
available even if the board-specific routing information is missing.
That will be addressed by another patch.
Fixes: 4bb90c87ab ("staging: comedi: add interface to ni routing table information")
Cc: <stable@vger.kernel.org> # 4.20+
Cc: Spencer E. Olson <olsonse@umich.edu>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200114182532.132058-2-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Advantech PCI-1713 has 32 analog input channels, but an incorrect
bit-mask in the definition of the `PCI171X_MUX_CHANH(x)` and
PCI171X_MUX_CHANL(x)` macros is causing channels 16 to 31 to be aliases
of channels 0 to 15. Change the bit-mask value from 0xf to 0xff to fix
it. Note that the channel numbers will have been range checked already,
so the bit-mask isn't really needed.
Fixes: 92c65e5553 ("staging: comedi: adv_pci1710: define the mux control register bits")
Reported-by: Dmytro Fil <monkdaf@gmail.com>
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20191227170054.32051-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "auto-attach" handler function `gsc_hpdi_auto_attach()` calls
`dma_alloc_coherent()` in a loop to allocate some DMA data buffers, and
also calls it to allocate a buffer for a DMA descriptor chain. However,
it does not check the return value of any of these calls. Change
`gsc_hpdi_auto_attach()` to return `-ENOMEM` if any of these
`dma_alloc_coherent()` calls fail. This will result in the comedi core
calling the "detach" handler `gsc_hpdi_detach()` as part of the
clean-up, which will call `gsc_hpdi_free_dma()` to free any allocated
DMA coherent memory buffers.
Cc: <stable@vger.kernel.org> #4.6+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20191216110823.216237-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The userspace comedilib function 'get_cmd_generic_timed' fills
the cmd structure with an informed guess and then calls the
function 'usbduxfast_ai_cmdtest' in this driver repeatedly while
'usbduxfast_ai_cmdtest' is modifying the cmd struct until it
no longer changes. However, because of rounding errors this never
converged because 'steps = (cmd->convert_arg * 30) / 1000' and then
back to 'cmd->convert_arg = (steps * 1000) / 30' won't be the same
because of rounding errors. 'Steps' should only be converted back to
the 'convert_arg' if 'steps' has actually been modified. In addition
the case of steps being 0 wasn't checked which is also now done.
Signed-off-by: Bernd Porr <mail@berndporr.me.uk>
Cc: <stable@vger.kernel.org> # 4.4+
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20191118230759.1727-1-mail@berndporr.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/comedi/drivers/ni_routes.c:52:21: warning:
route_table_size defined but not used [-Wunused-const-variable=]
It is never used since introduction.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20191023075206.33088-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/staging/comedi/drivers/dt3000.c: In function dt3k_ai_insn_read:
drivers/staging/comedi/drivers/dt3000.c:511:27: warning: variable aref set but not used [-Wunused-but-set-variable]
It is not used since commit 2e310235ca ("staging:
comedi: dt3000: rename dt3k_ai_insn()")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/1570520515-2186-7-git-send-email-zhengbin13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Variable fx2delay is being initialized with a value that is never read
and fx2delay is being re-assigned a little later on. The assignment is
redundant and hence can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190815105314.5756-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`dt3k_ns_to_timer()` determines the prescaler and divisor to use to
produce a desired timing period. It is influenced by a rounding mode
and can round the divisor up, down, or to the nearest value. However,
the code for rounding up currently does the same as rounding down! Fix
ir by using the `DIV_ROUND_UP()` macro to calculate the divisor when
rounding up.
Also, change the types of the `divider`, `base` and `prescale` variables
from `int` to `unsigned int` to avoid mixing signed and unsigned types
in the calculations.
Also fix a typo in a nearby comment: "improvment" => "improvement".
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190812120814.21188-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In `dt3k_ns_to_timer()` the following lines near the end of the function
result in a signed integer overflow:
prescale = 15;
base = timer_base * (1 << prescale);
divider = 65535;
*nanosec = divider * base;
(`divider`, `base` and `prescale` are type `int`, `timer_base` and
`*nanosec` are type `unsigned int`. The value of `timer_base` will be
either 50 or 100.)
The main reason for the overflow is that the calculation for `base` is
completely wrong. It should be:
base = timer_base * (prescale + 1);
which matches an earlier instance of this calculation in the same
function.
Reported-by: David Binderman <dcb314@hotmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20190812111517.26803-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove function db2k_initialize_dac as all it does is call
db2k_dac_disarm.
Modify call site accordingly.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190725052359.2308-1-nishkadg.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove function mite_request_channel_in_range as all it does is call
__mite_request_channel.
Rename __mite_request_channel to mite_request_channel_in_range and
change its type from static to non-static to maintain compatibility with
call sites.
Change only remaining call site of __mite_request_channel to call
mite_request_channel_in_range_instead.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20190701070025.3838-3-nishkadg.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove function gat_sce as all it does is call clk_gat_sce.
Modify call sites of the former to call the latter directly.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20190701070025.3838-2-nishkadg.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove function clk_sce as all it does is call clk_gat_sce.
Modify call site of clk_sce to call clk_gat_sce instead.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20190701070025.3838-1-nishkadg.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The interrupt handler `dt282x_interrupt()` causes a null pointer
dereference for those supported boards that have no analog output
support. For these boards, `dev->write_subdev` will be `NULL` and
therefore the `s_ao` subdevice pointer variable will be `NULL`. In that
case, the following call near the end of the interrupt handler results
in a null pointer dereference:
comedi_handle_events(dev, s_ao);
Fix it by only calling the above function if `s_ao` is valid.
(There are other uses of `s_ao` by the interrupt handler that may or may
not be reached depending on values of hardware registers. Trust that
they are reliable for now.)
Note:
commit 4f6f009b20 ("staging: comedi: dt282x: use comedi_handle_events()")
propagates an earlier error from
commit f21c74fa4c ("staging: comedi: dt282x: use cfc_handle_events()").
Fixes: 4f6f009b20 ("staging: comedi: dt282x: use comedi_handle_events()")
Cc: <stable@vger.kernel.org> # v3.19+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The interrupt handler `pci230_interrupt()` causes a null pointer
dereference for a PCI260 card. There is no analog output subdevice for
a PCI260. The `dev->write_subdev` subdevice pointer and therefore the
`s_ao` subdevice pointer variable will be `NULL` for a PCI260. The
following call near the end of the interrupt handler results in the null
pointer dereference for a PCI260:
comedi_handle_events(dev, s_ao);
Fix it by only calling the above function if `s_ao` is valid.
Note that the other uses of `s_ao` in the calls
`pci230_handle_ao_nofifo(dev, s_ao);` and `pci230_handle_ao_fifo(dev,
s_ao);` will never be reached for a PCI260, so they are safe.
Fixes: 39064f2328 ("staging: comedi: amplc_pci230: use comedi_handle_events()")
Cc: <stable@vger.kernel.org> # v3.19+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Comedi's acquisition buffer allocation code can allocate the buffer from
normal kernel memory or from DMA coherent memory depending on the
`dma_async_dir` value in the comedi subdevice. (A value of `DMA_NONE`
causes the buffer to be allocated from normal kernel memory. Other
values cause the buffer to be allocated from DMA coherent memory.) The
buffer currently consists of a bunch of page-sized blocks that are
vmap'ed into a contiguous range of virtual addresses. The pages are also
mmap'able into user address space. For DMA'able buffers, these
page-sized blocks are allocated by `dma_alloc_coherent()`.
For DMA-able buffers, the DMA API is currently abused in various ways,
the most serious abuse being the calling of `virt_to_page()` on the
blocks allocated by `dma_alloc_coherent()` and passing those pages to
`vmap()` (for mapping to the kernels vmalloc address space) and via
`page_to_pfn()` to `remap_pfn_range()` (for mmap'ing to user space). it
also uses the `__GFP_COMP` flag when allocating the blocks, and marks
the allocated pages as reserved (which is unnecessary for DMA coherent
allocations).
The code can be changed to get rid of the vmap'ed address altogether if
necessary, since there are only a few places in the comedi code that use
the vmap'ed address directly and we also keep a list of the kernel
addresses for the individual pages prior to the vmap operation. This
would add some run-time overhead to buffer accesses. The real killer is
the mmap operation.
For mmap, the address range specified in the VMA needs to be mmap'ed to
the individually allocated page-sized blocks. That is not a problem
when the pages are allocated from normal kernel memory as the individual
pages can be remapped by `remap_pfn_range()`, but it is a problem when
the page-sized blocks are allocated by `dma_alloc_coherent()` because
the DMA API currently has no support for splitting a VMA across multiple
blocks of DMA coherent memory (or rather, no support for mapping part of
a VMA range to a single block of DMA coherent memory).
In order to comply with the DMA API and allow the buffer to be mmap'ed,
the buffer needs to be allocated as a single block by a single call to
`dma_alloc_coherent()`, freed by a single call to `dma_free_coherent()`,
and mmap'ed to user space by a single call to `dma_mmap_coherent()`.
This patch changes the buffer allocation, freeing, and mmap'ing code to
do that, with the unfortunate consequence that buffer allocation is more
likely to fail. It also no longer uses the `__GFP_COMP` flag when
allocating DMA coherent memory, no longer marks the
allocated pages of DMA coherent memory as reserved, and no longer vmap's
the DMA coherent memory pages (since they are contiguous anyway).
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Variable fx2delay is being initialized to a value that is never read
and is being re-assigned a few statements later. The initialization
is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big staging and iio driver update for 5.2-rc1.
Lots of tiny fixes all over the staging and IIO driver trees here, along
with some new IIO drivers.
Also we ended up deleting two drivers, making this pull request remove a
few hundred thousand lines of code, always a nice thing to see. Both of
the drivers removed have been replaced with "real" drivers in their
various subsystem directories, and they will be coming to you from those
locations during this merge window.
There are some core vt/selection changes in here, that was due to some
cleanups needed for the speakup fixes. Those have all been acked by the
various subsystem maintainers (i.e. me), so those are ok.
We also added a few new drivers, for some odd hardware, giving new
developers plenty to work on with basic coding style cleanups to come in
the near future.
Other than that, nothing unusual here.
All of these have been in linux-next for a while with no reported
issues, other than an odd gcc warning for one of the new drivers that
should be fixed up soon.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging / IIO driver updates from Greg KH:
"Here is the big staging and iio driver update for 5.2-rc1.
Lots of tiny fixes all over the staging and IIO driver trees here,
along with some new IIO drivers.
The "counter" subsystem was added in here as well, as it is needed by
the IIO drivers and subsystem.
Also we ended up deleting two drivers, making this pull request remove
a few hundred thousand lines of code, always a nice thing to see. Both
of the drivers removed have been replaced with "real" drivers in their
various subsystem directories, and they will be coming to you from
those locations during this merge window.
There are some core vt/selection changes in here, that was due to some
cleanups needed for the speakup fixes. Those have all been acked by
the various subsystem maintainers (i.e. me), so those are ok.
We also added a few new drivers, for some odd hardware, giving new
developers plenty to work on with basic coding style cleanups to come
in the near future.
Other than that, nothing unusual here.
All of these have been in linux-next for a while with no reported
issues, other than an odd gcc warning for one of the new drivers that
should be fixed up soon"
[ I fixed up the warning myself - Linus ]
* tag 'staging-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (663 commits)
staging: kpc2000: kpc_spi: Fix build error for {read,write}q
Staging: rtl8192e: Remove extra space before break statement
Staging: rtl8192u: ieee80211: Fix if-else indentation warning
Staging: rtl8192u: ieee80211: Fix indentation errors by removing extra spaces
staging: most: cdev: fix chrdev_region leak in mod_exit
staging: wlan-ng: Fix improper SPDX comment style
staging: rtl8192u: ieee80211: Resolve ERROR reported by checkpatch
staging: vc04_services: bcm2835-camera: Compress two lines into one line
staging: rtl8723bs: core: Use !x in place of NULL comparison.
staging: rtl8723bs: core: Prefer using the BIT Macro.
staging: fieldbus: anybus-s: fix wait_for_completion_timeout return handling
staging: kpc2000: fix up build problems with readq()
staging: rtlwifi: move remaining phydm .h files
staging: rtlwifi: strip down phydm .h files
staging: rtlwifi: delete the staging driver
staging: fieldbus: anybus-s: rename bus id field to avoid confusion
staging: fieldbus: anybus-s: keep device bus id in bus endianness
Staging: sm750fb: Change *array into *const array
staging: rtl8192u: ieee80211: Fix spelling mistake
staging: rtl8192u: ieee80211: Replace bit shifting with BIT macro
...
Remove mmiowb() from the kernel memory barrier API and instead, for
architectures that need it, hide the barrier inside spin_unlock() when
MMIO has been performed inside the critical section.
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Merge tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull mmiowb removal from Will Deacon:
"Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())
Remove mmiowb() from the kernel memory barrier API and instead, for
architectures that need it, hide the barrier inside spin_unlock() when
MMIO has been performed inside the critical section.
The only relatively recent changes have been addressing review
comments on the documentation, which is in a much better shape thanks
to the efforts of Ben and Ingo.
I was initially planning to split this into two pull requests so that
you could run the coccinelle script yourself, however it's been plain
sailing in linux-next so I've just included the whole lot here to keep
things simple"
* tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (23 commits)
docs/memory-barriers.txt: Update I/O section to be clearer about CPU vs thread
docs/memory-barriers.txt: Fix style, spacing and grammar in I/O section
arch: Remove dummy mmiowb() definitions from arch code
net/ethernet/silan/sc92031: Remove stale comment about mmiowb()
i40iw: Redefine i40iw_mmiowb() to do nothing
scsi/qla1280: Remove stale comment about mmiowb()
drivers: Remove explicit invocations of mmiowb()
drivers: Remove useless trailing comments from mmiowb() invocations
Documentation: Kill all references to mmiowb()
riscv/mmiowb: Hook up mmwiob() implementation to asm-generic code
powerpc/mmiowb: Hook up mmwiob() implementation to asm-generic code
ia64/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
mips/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
sh/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
m68k/io: Remove useless definition of mmiowb()
nds32/io: Remove useless definition of mmiowb()
x86/io: Remove useless definition of mmiowb()
arm64/io: Remove useless definition of mmiowb()
ARM/io: Remove useless definition of mmiowb()
mmiowb: Hook up mmiowb helpers to spinlocks and generic I/O accessors
...
The "comedi_isadma" module calls `dma_alloc_coherent()` and
`dma_free_coherent()` with a NULL device pointer which is no longer
allowed. If the `hw_dev` member of the `struct comedi_device` has been
set to a valid device, that can be used instead. Unfortunately, all the
current users of the "comedi_isadma" module leave the `hw_dev` member
set to NULL. In that case, fall back to using the comedi "class" device
pointed to by the `class_dev` member if that is non-NULL. In that case,
make it "DMA-capable" with a coherent DMA mask set to the ISA bus limit
of 16MB (24 bits).
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Resolve the following warning from the Kconfig,
"WARNING: prefer 'help' over '---help---' for new help texts"
Signed-off-by: Moses Christopher <moseschristopherb@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`dt9812_detach()` is the Comedi "detach" handler for the dt9812 driver.
When it is called, the private data for the device is about to be freed.
The private data contains a mutex `devpriv->mut` that was initialized
when the private data was allocated. Call `mutex_destroy()` to mark it
as invalid.
Also remove the calls to `mutex_lock()` and `mutex_unlock()` from
`dt9812_detach()` as the mutex is only being used around a call to
`usb_set_intfdata()` to clear the USB interface's driver data pointer.
The mutex lock seems redundant here, especially as it is about to be
destroyed.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`ni6501_detach()` is the Comedi "detach" handler for the ni_usb6501
driver. It is called when the private data for the device is about to
be freed. The private data contains a mutex `devpriv->mut` that was
initialized when the private data was allocated. Call `mutex_destroy()`
to mark it as invalid.
Also remove the calls to `mutex_lock()` and `mutex_unlock()` from
`ni6501_detach()`. The only other locks of the mutex are by some of the
Comedi instruction handlers that cannot contend with the "detach"
handler for this mutex.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`usbdux_detach()` is the Comedi "detach" handler for the usbdux driver.
When it is called, the private data for the device is about to be freed.
The private date contains a mutex `devpriv->mut` that was initialized
when the private data was allocated. Call `mutex_destroy()` to mark it
as invalid.
The calls to `mutex_lock()` and `mutex_unlock()` are probably not
required, especially as the mutex is about to be destroyed, but leave
them alone for now.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`usbduxfast_detach()` is the Comedi "detach" handler for the usbduxfast
driver. When it is called, the private data for the device is about to
be freed. The private date contains a mutex `devpriv->mut` that was
initialized when the private data was allocated. Call `mutex_destroy()`
to mark it as invalid.
The calls to `mutex_lock()` and `mutex_unlock()` in
`usbduxfast_detach()` are probably not required, especially as the mutex
is about to be destroyed, but leave them alone for now.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`usbduxsigma_detach()` is the Comedi "detach" handler for the
usbduxsigma driver. When it is called, the private data for the device
is about to be freed. The private date contains a mutex `devpriv->mut`
that was initialized when the private data was allocated. Call
`mutex_destroy()` to mark it as invalid.
The calls to `mutex_lock()` and `mutex_unlock()` in
`usbduxsigma_detach()` are probably not required, especially as the
mutex is about to be destroyed, but leave them alone for now.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are not a lot of functions in the core comedi module that require
the R/W semaphore `attach_lock` in `struct comedi_device` to be locked
(although there are a few functions that require at least one of
`attach_lock` and `mutex` to be locked). One function that requires the
caller to lock `attach_lock` is `comedi_device_detach_cleanup()` so add
a call to `lockdep_assert_held()` to check and document that.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lots of functions in the core comedi module expect the mutex in `struct
comedi_device` to be held, so add calls to `lockdep_assert_held()` to
check and document that. An unusual case is the calls to
`lockdep_assert_held()` after successful return from
`comedi_alloc_board_minor()` which allocates a `struct comedi_device`
and returns with its mutex locked.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`comedi_auto_config()` uses `dev->class_dev` for logging a kernel
message after releasing `dev->mutex`. There is an unlikely possibility
that the Comedi device `dev` will have been removed by the
`COMEDI_DEVCONFIG` ioctl() command. Keep hold of the mutex until the
kernel message has been sent to prevent that. The function can call
`comedi_release_hardware_device()` on error. In that case, the mutex
must be unlocked before that.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Xiyu Yang