linux.git/drivers/staging/comedi/drivers.c, branch v3.14

staging: comedi: fix too early cleanup in comedi_auto_config()

2014-02-07T19:08:46+00:00

`comedi_auto_config()` is usually called from the probe routine of a
low-level comedi driver to allocate and auto-configure a comedi device.
Part of this involves calling the low-level driver's `auto_attach()`
handler, and if that is successful, `comedi_device_postconfig()` tries
to complete the configuration of the comedi device.  If either of those
fail, `comedi_device_detach()` is called to clean up, and
`comedi_release_hardware_device()` is called to remove the dynamically
allocated comedi device.

Unfortunately, `comedi_device_detach()` clears the `hw_dev` member of
the `struct comedi_device` (indirectly via `comedi_clear_hw_dev()`), and
that stops `comedi_release_hardware_device()` finding the comedi device
associated with the hardware device, so the comedi device won't be
removed properly.

Since `comedi_release_hardware_device()` also calls
`comedi_device_detach()` (assuming it finds the comedi device associated
with the hardware device), the fix is to remove the direct call to
`comedi_device_detach()` from `comedi_auto_config()` and let the call to
`comedi_release_hardware_device()` take care of it.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

staging: comedi: report success/failure of autoconfig

2014-01-09T18:51:54+00:00

Added success message to the driver autoconfig and error
message in case it fails. A success message is required
so that the user can find out which comedi driver has been
associated with which udev device. This also makes troubleshooting
much easier when more than one card is in the computer or
there is a mix of USB and PCI devices.
As Ian suggested we should report both the driver and the board
which might have different names, especially if one driver covers a
range of different boards.

Signed-off-by: Bernd Porr 
Reviewed-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

Merge 3.13-rc5 into staging-next

2013-12-24T18:06:37+00:00

This resolves a merge issue with drivers/staging/imx-drm/imx-drm-core.c

Signed-off-by: Greg Kroah-Hartman

staging: comedi: drivers: fix return value of comedi_load_firmware()

2013-12-17T21:05:53+00:00

Some of the callback functions that upload the firmware in the comedi
drivers return a positive value indicating the number of bytes sent
to the device. Detect this condition and just return '0' to indicate
a successful upload.

Reported-by: Bernd Porr 
Signed-off-by: H Hartley Sweeten 
Acked-by: Ian Abbott 
Acked-by: Dan Carpenter 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

staging: comedi: use refcount in comedi_driver_unregister()

2013-11-12T00:16:44+00:00

Change `comedi_driver_unregister()` to call
`comedi_dev_get_from_minor()` instead of `comedi_dev_from_minor()` when
finding devices using the driver.  This increments the reference count
to prevent the device being removed while it is being checked to see if
it is attached to the driver.  Call `comedi_dev_put()` to decrement the
reference afterwards.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

staging: comedi: add detachment counter for validity checks

2013-11-12T00:16:44+00:00

Add a member `detach_count` to `struct comedi_device` that is
incremented every time the device gets detached.  This will be used in
some validity checks in the 'read' and 'write' file operations to make
sure the attachment remains valid.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

staging: comedi: cancel commands before detaching device

2013-11-12T00:16:44+00:00

The comedi core module's handling of the `COMEDI_DEVCONFIG` ioctl will
not allow a device to be detached if it is busy.  However, comedi
devices can also be auto-detached due to a removal of a hardware device.
One of the things we should do in that case is cancel any asynchronous
commands that are running.  Add a new function
`comedi_device_cancel_all()` to do that and call it from
`comedi_device_detach()`.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

staging: comedi: cleanup_device() -> comedi_device_detach_cleanup()

2013-11-12T00:16:43+00:00

Rename the local function `cleanup_device()` to
`comedi_device_detach_cleanup()`.  It is only called from the
`comedi_device_detach()` function and that is called from
`comedi_device_cleanup()` and other places.  The more specific function
name seems less confusing.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

staging: comedi: use attach_lock semaphore during attach and detach

2013-11-12T00:16:43+00:00

Acquire the `attach_lock` semaphore in the `struct comedi_device` while
modifying the `attached` flag.  This is a "write" acquire.  Note that
the main mutex in the `struct comedi_device` is also held at this time.
Tasks wishing to check the device is attached will need to either
acquire the main mutex, or "read" acquire the `attach_lock` semaphore,
or both in that order.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

staging: comedi: drivers: introduce comedi_dio_update_state()

2013-09-17T14:47:40+00:00

The (*insn_bits) functions for DIO and DO subdevices typically use
the subdevice 's->state' to hold the current state of the output
channels. The 'insn' passed to these functions, INSN_BITS, specifies
two parameters passed in the 'data'.

  data[0] = 'mask', the channels to update
  data[1] = 'bits', the new state for the channels

Introduce a helper function to handle the boilerplate used to
update the internal state.

Note that the 'mask' is filtered by the 'chanmask' of the channels
actually supported by the subdevice. This is used to protect any
non-channel related bits that are stored in the subdevice state.

Signed-off-by: H Hartley Sweeten 
Reviewed-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman