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commit 67aa4acbc97f6a55b328e4e2305ef19cbe949d85 upstream.
`comedi_alloc_spriv()` allocates private storage for a comedi subdevice
and sets the `SRF_FREE_SPRIV` flag in the `runflags` member of the
subdevice to allow the private storage to be automatically freed when
the comedi device is being cleaned up. Unfortunately, the flag gets
clobbered by `do_cmd_ioctl()` which calls
`comedi_set_subdevice_runflags()` with a mask value `~0` and only the
`SRF_USER` and `SRF_RUNNING` flags set, all the other SRF flags being
cleared.
Change the calls to `comedi_set_subdevice_runflags()` that currently use
a mask value of `~0` to use a more relevant mask value. For
`do_cmd_ioctl()`, the relevant SRF flags are `SRF_USER`, `SRF_ERROR` and
`SRF_RUNNING`. (At one time, `SRF_RT` would be included in that set of
flags, but it is no longer used.) For `comedi_alloc_spriv()` replace
the call to `comedi_set_subdevice_runflags()` with a simple
OR-assignment to avoid unnecessary use of a spin-lock.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging tree merge from Greg KH:
"Here's the bit staging tree pull request for 3.12-rc1.
Lots of staging driver updates, and fixes. Lustre is finally enabled
in the build, and lots of cleanup started happening in it. There's a
new wireless driver in here, and 2 new TTY drivers, which cause the
overall lines added/removed to be quite large on the "added" side.
The IIO driver updates are also coming through here, as they are tied
to the staging iio drivers"
* tag 'staging-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (942 commits)
staging: dwc2: make dwc2_core_params documentation more complete
staging: dwc2: validate the value for phy_utmi_width
staging: dwc2: interpret all hwcfg and related register at init time
staging: dwc2: properly mask the GRXFSIZ register
staging: dwc2: remove redundant register reads
staging: dwc2: re-use hptxfsiz variable
staging: dwc2: simplify debug output in dwc_hc_init
staging: dwc2: add missing shift
staging: dwc2: simplify register shift expressions
staging: dwc2: only read the snpsid register once
staging: dwc2: unshift non-bool register value constants
staging: dwc2: fix off-by-one in check for max_packet_count parameter
staging: dwc2: remove specific fifo size constants
Staging:BCM:DDRInit.c:Renaming __FUNCTION__
staging: bcm: remove Version.h file.
staging: rtl8188eu: off by one in rtw_set_802_11_add_wep()
staging: r8188eu: copying one byte too much
staging: rtl8188eu: || vs && typo
staging: r8188eu: off by one bugs
staging: crystalhd: Resolve sparse 'different base types' warnings.
...
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We want these fixes in this branch.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We want these fixes here.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The dev_attrs field of struct class is going away soon, dev_groups
should be used instead. This converts the comedi class code to use the
correct field.
Cc: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`do_cmd_ioctl()` is called with the comedi device's mutex locked to
process the `COMEDI_CMD` ioctl to set up comedi's asynchronous command
handling on a comedi subdevice. `comedi_read()` and `comedi_write()`
are the `read` and `write` handlers for the comedi device, but do not
lock the mutex (for performance reasons, as some things can hold the
mutex for quite a long time).
There is a race condition if `comedi_read()` or `comedi_write()` is
running at the same time and for the same file object and comedi
subdevice as `do_cmd_ioctl()`. `do_cmd_ioctl()` sets the subdevice's
`busy` pointer to the file object way before it sets the `SRF_RUNNING` flag
in the subdevice's `runflags` member. `comedi_read() and
`comedi_write()` check the subdevice's `busy` pointer is pointing to the
current file object, then if the `SRF_RUNNING` flag is not set, will call
`do_become_nonbusy()` to shut down the asyncronous command. Bad things
can happen if the asynchronous command is being shutdown and set up at
the same time.
To prevent the race, don't set the `busy` pointer until
after the `SRF_RUNNING` flag has been set. Also, make sure the mutex is
held in `comedi_read()` and `comedi_write()` while calling
`do_become_nonbusy()` in order to avoid moving the race condition to a
point within that function.
Change some error handling `goto cleanup` statements in `do_cmd_ioctl()`
to simple `return -ERRFOO` statements as a result of changing when the
`busy` pointer is set.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Comedi devices can do blocking read() or write() (or poll()) if an
asynchronous command has been set up, blocking for data (for read()) or
buffer space (for write()). Various events associated with the
asynchronous command will wake up the blocked reader or writer (or
poller). It is also possible to force the asynchronous command to
terminate by issuing a `COMEDI_CANCEL` ioctl. That shuts down the
asynchronous command, but does not currently wake up the blocked reader
or writer (or poller). If the blocked task could be woken up, it would
see that the command is no longer active and return. The caller of the
`COMEDI_CANCEL` ioctl could attempt to wake up the blocked task by
sending a signal, but that's a nasty workaround.
Change `do_cancel_ioctl()` to wake up the wait queue after it returns
from `do_cancel()`. `do_cancel()` can propagate an error return value
from the low-level comedi driver's cancel routine, but it always shuts
the command down regardless, so `do_cancel_ioctl()` can wake up he wait
queue regardless of the return value from `do_cancel()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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All the ioport resources are managed by the comedi core. None of
the drivers depend on <linux/ioport.h>. Remove the includes.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second set of VFS changes from Al Viro:
"Assorted f_pos race fixes, making do_splice_direct() safe to call with
i_mutex on parent, O_TMPFILE support, Jeff's locks.c series,
->d_hash/->d_compare calling conventions changes from Linus, misc
stuff all over the place."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
Document ->tmpfile()
ext4: ->tmpfile() support
vfs: export lseek_execute() to modules
lseek_execute() doesn't need an inode passed to it
block_dev: switch to fixed_size_llseek()
cpqphp_sysfs: switch to fixed_size_llseek()
tile-srom: switch to fixed_size_llseek()
proc_powerpc: switch to fixed_size_llseek()
ubi/cdev: switch to fixed_size_llseek()
pci/proc: switch to fixed_size_llseek()
isapnp: switch to fixed_size_llseek()
lpfc: switch to fixed_size_llseek()
locks: give the blocked_hash its own spinlock
locks: add a new "lm_owner_key" lock operation
locks: turn the blocked_list into a hashtable
locks: convert fl_link to a hlist_node
locks: avoid taking global lock if possible when waking up blocked waiters
locks: protect most of the file_lock handling with i_lock
locks: encapsulate the fl_link list handling
locks: make "added" in __posix_lock_file a bool
...
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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As suggested by Ian Abbott, comedi_set_spriv() can only be used to
set the subdevice->private pointer to something that can be kfree()'d.
Rename the function to comedi_alloc_spriv() and have it kzalloc() the
memory as well as set the private pointer. This saves a function call
in the drivers and avoids the possibility of incorrectly calling
comedi_set_spriv() for some pointer that is not meant to be kfree()'d.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Introduce a new subdevice runflags, SRF_FREE_SPRIV, and a new helper
function, comedi_set_spriv(), that the drivers can use to set the
comedi_subdevice private data pointer. The helper function will also
set SRF_FREE_SPRIV to allow the comedi core to automatically free the
subdevice private data during the cleanup_device() stage of the detach.
Currently s->private is only allocated by the 8255, addi_watchdog,
amplc_dio200_common, and ni_65xx drivers. All users of those drivers
can then have the comedi_spriv_free() calls removed and in many cases
the (*detach) can then simply be the appropriate comedi core provided
function.
The ni_65xx driver uses a helper function, ni_65xx_alloc_subdevice_private(),
to allocate the private data. Refactor the function to return an errno
or call comedi_set_spriv() instead of returning a pointer to the private
data and requiring the caller to handle it.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Type of variable 'bi' is struct comedi_bufinfo and 'subdevice' is
defined as unsigned, so there is no need to check if it is less then
zero.
Signed-off-by: Güngör Erseymen <gelurine@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Type of variable 'bc' is struct comedi_bufconfig and 'subdevice' is
defined as unsigned, so there is no need to check if it is less then
zero.
Signed-off-by: Güngör Erseymen <gelurine@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We want the changes here, and we resolve the merge conflict that was
happening in the nvec_kbd.c file.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When a comedi device is successfully attached, those subdevices that
support asynchronous commands will have had buffers allocated
successfully. It is possible to resize the buffers afterwards, but if
the resize fails the subdevice is left with no buffer
(`s->async->prealloc_buf == NULL`). Currently, this also causes any
subsequent attempts to resize the buffer to fail with an error, which
seems like a bad idea.
Remove the check in `resize_async_buffer()` that causes the resize to
fail if the subdevice currently has no buffer (presumably due to the
failure of a previous resize attempt). Callers of
`resize_async_buffer()` have already checked that the subdevice is
allowed to have a buffer.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Addresses change...
Remove the paragraph with the FSF address from all the comedi source
files.
Also, remove the paragraph about the finding the complete GPL in the
COPYING file since it's unnecessary.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Comedi is licensed under GPL. Some if its exports are currently
EXPORT_SYMBOL() and others are EXPORT_SYMBOL_GPL(). Change them all
to EXPORT_SYMBOL_GPL() and see if anyone reports any fall out.
If any of the symbols "need" to be EXPORT_SYMBOL() they will be
addressed as needed.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add local function `comedi_clear_board_dev()` as a safer alternative to
`comedi_clear_board_minor()` when we already have a pointer to a `struct
comedi_device`. It uses the board minor device number stored in the
`struct comedi_device` (which must have already been initialized) and
only clears the entry in `comedi_board_minor_table[]` if it points to
the specified `struct comedi_device`. Rather than returning the old
table entry, it returns `true` if the entry matched (and so has just
been cleared) and returns `false` otherwise.
Call `comedi_clear_board_dev()` instead of `comedi_clear_board_minor()`
in `comedi_unlocked_ioctl()` (in the code that frees a dynamically
allocated comedi device detached by the `COMEDI_DEVCONFIG` ioctl). That
ought to return `true` but check it just in case before freeing the
device. There is still a race condition here which needs to be dealt
with once we've implemented reference counting for `struct
comedi_device`s.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`struct comedi_file_info` is no longer used so remove it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_alloc_board_minor()` allocates and initializes a `struct
comedi_file_info` and a `struct comedi_device`, and assigns a board
minor device number (if there are any available), storing a pointer to
the allocated `struct comedi_file_info` in
`comedi_board_minor_table[minor]` where `minor` is the board minor
device number.
There is no longer anything useful in the `struct comedi_file_info`
apart from the pointer to the `struct comedi_device` that was allocated,
so the `struct comedi_file_info` is superfluous.
Change `comedi_board_minor_table[]` to hold pointers to the actual
`struct comedi_device`'s. `comedi_alloc_board_minor()` no longer needs
to allocate a `struct comedi_file_info`. Replace
`comedi_free_board_file_info()` with `comedi_free_board_dev()` with its
parameter pointing to the `struct comedi_device` to be freed (there is
no longer a `struct comedi_file_info` to be freed).
There are consequential changes to `comedi_dev_from_board_minor()`,
`comedi_clear_board_minor()` (which now returns a `struct comedi_device
*`), `comedi_free_board_minor()`, `comedi_release_hardware_device()` and
`comedi_unlocked_ioctl()` (when dealing with detachment of a dynamically
allocated comedi device by the `COMEDI_DEVCONFIG` ioctl).
`comedi_dev_from_file_info()` is no longer used as a result of the above
changes so remove it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_alloc_subdevice_minor()` allocates and initializes a `struct
comedi_file_info` and assigns a subdevice minor device number (if there
are any available), storing a pointer to the allocated `struct
comedi_file_info` in `comedi_subdevice_minor_table[i]` where `i` is the
array index corresponding to the subdevice minor device number (indexed
by subdevice minor device number minus `COMEDI_NUM_BOARD_MINORS`).
The information stored in the `struct comedi_file_info` can be derived
from the subdevice structure (`struct comedi_subdevice`) itself, so the
`struct comedi_file_info` is superfluous.
Change `comedi_subdevice_minor_table[]` to hold pointers to the actual
`struct comedi_subdevice`'s. `comedi_alloc_subdevice_minor()` no longer
needs to allocate a `struct comedi_file_info` and
`comedi_free_subdevice_info()` no longer has a `struct comedi_file_info`
to free.
Replace `comedi_file_info_from_minor()` with
`comedi_subdevice_from_minor()`, returning a (possibly NULL) pointer to
a `struct comedi_subdevice` from the table. This has knock-on effects
for `comedi_dev_from_subdevice_minor()`, `comedi_read_subdevice()` and
`comedi_write_subdevice()`. In particular, `comedi_read_subdevice()`
and `comedi_write_subdevice()` now need to check the subdevice flags to
see if the determine whether to override the comedi device's default
read/write subdevice.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge the code from `comedi_file_info_from_board_minor()` into
`comedi_dev_from_board_minor()` and remove it since nothing else calls
it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge the code from `comedi_clear_subdevice_minor()` into
`comedi_free_subdevice_minor()` and remove it since nothing else calls
it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Refactor `comedi_dev_from_minor()` to call one of two new functions
`comedi_dev_from_board_minor()` (for minor device numbers less than
`COMEDI_NUM_BOARD_MINORS`) or `comedi_dev_from_subdevice_minor()` (for
minor device numbers greater than or equal to `COMEDI_NUM_BOARD_MINORS`,
which are subdevice minor device numbers).
Remove `comedi_file_info_from_minor()` as it is no longer used.
This is a step towards removing `struct comedi_file_info`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Since the parameters of `comedi_read_subdevice()` and
`comedi_write_subdevice()` have changed, there is no longer a need to
keep a local variable `struct comedi_file_info *info` hanging around in
the file operation functions and device attribute access functions.
Remove the variable from those function and replace the call sequence
`info = comedi_file_info_from_minor(minor)`, `dev =
comedi_dev_from_file_info(info)` with the simpler `dev =
comedi_dev_from_minor(minor)`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_read_subdevice()` and `comedi_write_subdevice()` currently take
a single parameter pointing to a `struct comedi_file_info`. I'm trying
to get rid of `struct comedi_file_info` so as part of that plan,
`comedi_read_subdevice()` and `comedi_write_subdevice()` need to change.
Change them to take two parameters: a pointer to a `struct
comedi_device` and a minor device number. If the minor device number is
a "board" minor device number (`minor < COMEDI_NUM_BOARD_MINORS`) we'll
always return the default read or write subdevice. If the minor device
number if a "subdevice" minor device number a different read or write
subdevice may be returned. In that case, use the subdevice minor device
number to look up the information about whether the default read or
write subdevice needs to be overridden.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The comedi device attribute functions such as
`show_max_read_buffer_kb()` call `dev_get_drvdata()` to get a pointer to
a `struct comedi_file_info` from the private driver data field of class
device. Change them to use the minor device number to look up this
pointer value so they behave more like the file operation functions.
Check the pointer is non-NULL as the entry in the minor device table
could have been set to NULL. Note that there is still a race condition
in the use of this pointer value after acquiring the mutex which needs
to be dealt with once reference counting has been implemented for comedi
devices.
The calls to `dev_set_drvdata()` from `comedi_alloc_board_minor()` and
`comedi_alloc_subdevice_minor()` are no longer needed so remove them.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The comedi device attribute functions such as
`show_read_buffer_kb()` or `show_write_buffer_kb()` call
`comedi_read_subdevice()` or `comedi_write_subdevice()` without
acquiring the comedi device's mutex first, although the functions do
acquire the mutex afterwards. Change them to acquire the mutex first.
This is consistent with most of the comedi device file operation
functions (apart from `comedi_read()` and `comedi_write()` which
probably need looking at).
Despite the use of the mutex, there are still race conditions as the
`struct comedi_file_info *info` variable value set before acquiring the
mutex could be stale after acquiring the mutex. This problem will be
dealt with once reference counting has been implemented for the comedi
devices.
This patch also adds local variable `struct comedi_device *dev` to the
functions to reduce the use of the `info` variable a little bit.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Most of the comedi core uses the identifier `dev` to point to a `struct
comedi_device`. The device sysfs attribute functions such as
`show_max_read_buffer_kb()` use the parameter id `dev` to point to a
`struct device`. Rename the parameter to `csdev` for "class device" for
consistency with the functions that call `device_create()` to create
these class devices (`comedi_alloc_board_minor()` and
`comedi_alloc_subdevice_minor()`).
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The `hardware_device` member of `struct comedi_device_info` is only set
to point to a hardware device by the auto-configuration code (specifically
`comedi_alloc_board_minor() with a non-NULL `hardware_device` parameter)
so that it can be found again by the auto-unconfiguration code
(specifically `comedi_release_hardware_device()`). However, as
`info->device->hw_dev` (where `info` is a pointer to the `struct
comedi_device_info`) is set to the same value as `info->hardware_device`
(by calling `comedi_set_hw_dev()` with the same hardware device pointer)
we can look for that instead, so there is no need for the
`hardware_device` member any more. Get rid of it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_clear_minor()` calls either `comedi_clear_board_minor()` or
`comedi_clear_subdevice_minor()` depending on its minor device number
parameter. The one it calls only depends on where it is called from, so
bypass the calls to `comedi_clear_minor()` and remove it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The comedi core reserves minor device numbers from 0 to
`COMEDI_NUM_BOARD_MINORS - 1` (0 to 0x30 - 1) for the main comedi
"board" devices and reserves minor device numbers from
`COMEDI_NUM_BOARD_MINORS` to `COMEDI_NUM_MINORS - 1` (0x30 to 0x100 - 1)
for comedi subdevices (or at least those that claim to support
asynchronous comedi commands). There is an array
`comedi_file_info_table[COMEDI_NUM_MINORS]` used to hold pointers to
information for each board minor device number and subdevice minor
device number that has been allocated (with NULL pointers for those not
allocated), along with a protective lock `comedi_file_info_table_lock`.
Since the ranges of board minor device numbers and subdevice minor
device numbers do not overlap, we can use separate tables and separate
locks for the different types of minor device numbers. This will allow
us to use different pointer types for the elements of each table in the
future without just using a generic `void *`. (At the moment, the table
elements point to a `struct comedi_file_info` allocated dynamically for
each allocated board minor device or subdevice minor device, but I plan
to get rid of that data structure.)
Replace `comedi_file_info_table[COMEDI_NUM_MINORS]` with two new arrays
of the same type, `comedi_board_minor_table[COMEDI_NUM_BOARD_MINORS]`
for board minors, and
`comedi_subdevice_minor_table[COMEDI_NUM_SUBDEVICE_MINORS]` for
subdevice minors (where `COMEDI_NUM_SUBDEVICE_MINORS` is
`COMEDI_NUM_MINORS - COMEDI_NUM_BOARD_MINORS`).
`comedi_subdevice_minor_table[]` is indexed by the subdevice minor
number minus `COMEDI_NUM_BOARD_MINORS` since `COMEDI_NUM_BOARD_MINORS`
is the first valid subdevice minor number.
Replace `comedi_file_info_table_lock` with
`comedi_board_minor_table_lock` for board minors and
`comedi_subdevice_minor_table_lock` for subdevice minors.
Refactor `comedi_clear_minor()` to call one of two new functions
`comedi_clear_board_minor()` and `comedi_clear_subdevice_minor()`
depending on the minor device number passed as a parameter. Similarly,
refactor `comedi_file_info_from_minor()` to call one of two new
functions `comedi_file_info_from_board_minor()` and
`comedi_file_info_from_subdevice_minor()` depending on the minor device
number parameter.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The macro `COMEDI_FIRST_SUBDEVICE_MINOR` just expands to another macro
`COMEDI_NUM_BOARD_MINORS`. Replace uses of
`COMEDI_FIRST_SUBDEVICE_MINOR` with `COMEDI_NUM_BOARD_MINORS` and get
rid of the former.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The macro definitions `COMEDI_NUM_MINORS` and
`COMEDI_FIRST_SUBDEVICE_MINOR` are only used in "comedi_fops.c" so move
them to there from "comedidev.h".
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The spin-lock `comedi_file_info_table_lock` is used to protect against
simultaneous modification and access of `comedi_file_info_table[]`.
Change it from a spin-lock to a mutex as it is only used in contexts
where sleeping is allowed.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Call `comedi_set_hw_dev()` to set the `hw_dev` member of `struct
comedi_device` in `comedi_alloc_board_minor()` instead of in
`comedi_auto_config()`. Don't bother to check for an error returned by
`comedi_set_hw_dev()` here; it only fails when changing a non-NULL
pointer to a different non-NULL pointer and since the `struct
comedi_device` has just been allocated and initialized, its `hw_dev`
will be NULL already. Calling `comedi_set_hw_dev()` with a non-NULL
hardware device pointer increments the kref counter for the hardware
device.
If `comedi_alloc_board_minor()` fails further down the function, we rely
on its call to `comedi_device_cleanup()` to call `comedi_clear_hw_dev()`
(via `comedi_device_detach()` and `cleanup_device()`) to clear `hw_dev`
and decrement its kref counter. (That's the "beneficial side-effect"
mentioned in the patch that replaced `__comedi_device_detach()`.)
Remove the call to `comedi_set_hw_dev()` from `comedi_auto_config()` as
the call to `comedi_alloc_board_minor()` does it for us.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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For a legacy device attachment with the `COMEDI_DEVCONFIG` ioctl,
`do_devconfig_ioctl()` calls `comedi_device_attach()` to find a matching
device driver and attach the device. It then tries to increment the
device driver's module count and if that fails it detaches the device.
So on successful attachment of a device by the `COMEDI_DEVCONFIG` ioctl,
the device driver's module count will have been incremented.
`comedi_device_attach()` is called from nowhere else. It already
increments the device driver's module count temporarily and decrements
it again; if it gets as far as calling `comedi_device_postconfig()` the
module count is decremented within that function.
Simplify the above by removing the decrement of the device driver module
count from `comedi_device_postconfig()`. If the call to
`comedi_device_postconfig()` succeeds, `comedi_device_attach()` will
return with the module count still incremented, otherwise decrement the
module count before returning the error. Don't try and increment the
module count in `do_devconfig_ioctl()` after a successful return from
`comedi_device_attach()` as the module count has now already been
incremented.
`comedi_device_postconfig()` is also called by `comedi_auto_config()`
which currently has to increment the device driver's module count
temporarily so that `comedi_device_postconfig()` can decrement it, but
always returns with no overall change to the module count. Remove all
the module count manipulations from `comedi_device_postconfig()`. There
is no other reason for `comedi_auto_config()` to increment the device
driver's module count temporarily, since it is only called (indirectly)
from the device driver itself (usually via one of the wrappers
`comedi_pci_auto_config()` or `comedi_usb_auto_config()`).
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Move a few functions and variables to avoid a couple of forward
declarations.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If a dynamically allocated (non-legacy, and automatically configured)
comedi device has been successfully unconfigured by use of the
`COMEDI_DEVCONFIG` ioctl, then remove the device afterwards.
(Dynamically identified comedi devices are identified by their minor
device number being `comedi_num_legacy_minors` or greater.) This is
done in `comedi_unlocked_ioctl()` on return from `do_devconfig_ioctl()`.
Note that there is an unlikely race condition with some other thread
that has just called `comedi_file_info_from_minor()` or
`comedi_dev_from_minor()` and is about to use the device, but that race
condition also exists for automatically removed devices and will be
dealt with properly once reference counting of comedi devices has been
implemented. We do avoid a race condition between automatic removal and
removal by the `COMEDI_DEVCONFIG` ioctl though.
Also add an extra precaution in `do_devconfig_ioctl()` to avoid
configuring a dynamically allocated device since there is a tight
window avoiding the race condition where this could happen and the
device is about to be removed anyway.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When `comedi_unlocked_ioctl()` handled the `COMEDI_DEVCONFIG` ioctl via
a call to `do_devconfig()`, this used to be allowed to attach a legacy
hardware device to any board minor device, and the auto-unconfiguration
code for non-legacy used to search all board minor devices to find the
hardware device being removed. After calling `do_devconfig()`
successfully, `comedi_unlocked_ioctl()` sets the `hardware_device`
member of the `struct comedi_file_info` to NULL to stop the
auto-unconfiguration code finding it by accident and unconfiguring the
wrong comedi device as a result.
The above is no longer necessary because `do_devconfig()` now only
allows legacy hardware devices to be attached to comedi board minor
device numbers below `comedi_num_legacy_minors` and the
auto-unconfiguration code (particularly
`comedi_release_hardware_device()`) only searches comedi board minor
device numbers greater than or equal to `comedi_num_legacy_minors`, so
there is no overlap.
Remove the now unnecessary setting of `info->hardware_device = NULL` in
`comedi_unlocked_ioctl()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_alloc_board_minor()` is called for both reserved "legacy"
devices created during module initialization, and for dynamically
created devices (via `comedi_auto_config()`). All the minor device
numbers from 0 to `comedi_num_legacy_minors - 1` are for legacy devices
and all those from `comedi_num_legacy_minors` to
`COMEDI_NUM_BOARD_MINORS - 1` are for dynamically created devices.
`comedi_release_hardware_device()` is called (via
`comedi_auto_unconfig()`) when a dynamically created device is being
removed. It needs to search the table of minor device numbers to see
which one is associated with the hardware device. It currently starts
the search at minor device number 0. Change it to start from
`comedi_num_legacy_minors` to skip over those belonging to legacy
devices. Also change `comedi_alloc_board_minor()` to skip the legacy
devices when searching for a free minor device number for the
dynamically created device. (The validity of the `hardware_device`
parameter is used to distinguish the legacy devices from the dynamically
created ones.)
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Return from `comedi_alloc_board_minor()` with the mutex of the created
`struct comedi_device` pre-locked. This allows further initialization
by the caller without the worry of something getting in there first.
`comedi_auto_config()` no longer needs to check if the device is already
"attached" since whatever was trying to attach the device would need to
have locked the mutex first.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Change `comedi_alloc_board_minor()` to return a pointer to the allocated
`struct comedi_device` instead of a minor device number. Return an
`ERR_PTR()` value on error instead of a negative error number. This
saves a call to `comedi_dev_from_minor()` in `comedi_auto_config()`.
Also change it to use a local variable `dev` to hold the pointer to the
`struct comedi_device` instead of using `info->device` all the time.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_free_board_minor()` is now only called from the same .c file it
is defined in, so give it static linkage.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add `comedi_release_hardware_device()` as a replacement for the call
sequence `comedi_find_board_minor()`, `comedi_free_board_minor()`. This
is slightly safer as we can make sure nothing funny happens to the found
`comedi_file_info_table[]` entry in the middle of the sequence. Change
`comedi_auto_unconfig()` to call the new function instead of the old
sequence. Remove `comedi_find_board_minor()` as it has no other
callers.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Split out the part of `comedi_free_board_minor()` that clears the
`comedi_file_info_table[]` element into new function
`comedi_clear_minor()`. Split out the remainder of the original
function into new function `comedi_free_board_file_info()`.
Also re-use a call to `comedi_clear_minor()` in
`comedi_free_subdevice_minor()` instead of doing the same thing inline.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_device_cleanup()` is called just before freeing a comedi device.
It is possible for the device to still be open in which case the module
reference counts for the core comedi module and possibly the low-level
driver module will remain out of whack because `comedi_close()` will not
find the comedi device and so will not decrement the module counts.
This really needs to be handled better, but for now decrement the module
counts in `comedi_device_cleanup()` according to the number of
outstanding opens.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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`comedi_device_init()` is only called from one place
(`comedi_alloc_board_minor()`) and the `struct comedi_device` has
already been zeroed out by `kzalloc()`. Don't bother zeroing it out
again with `memset()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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In the comedi core module, `comedi_file_info_table[]` is tentatively
defined in the .bss section, so will already be zeroed out on
initialization. Don't bother zeroing it out again in the module
initialization function `comedi_init()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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