kernel/linux.git/drivers/staging/comedi, branch v3.15.2

staging: comedi: ni_daq_700: add mux settling delay

2014-05-23T16:31:35+00:00

I got a patch from the original author, Fred Brooks, to add a small settling delay after setting the AI channel multiplexor. The lack of delay resulted in unstable or scrambled data on faster processors. Signed-off-by: Ian Abbott Reported-by: Fred Brooks Cc: # 3.7.x - 3.15.x Signed-off-by: Greg Kroah-Hartman

staging: comedi: usbdux: bug fix for accessing 'ao_chanlist' in private data

2014-04-23T23:20:15+00:00

In usbdux_ao_cmd(), the channels for the command are transfered from the cmd->chanlist and stored in the private data 'ao_chanlist'. The channel numbers are bit-shifted when stored so that they become the "command" that is transfered to the device. The channel to command conversion results in the 'ao_chanlist' having these values for the channels: channel 0 -> ao_chanlist = 0x00 channel 1 -> ao_chanlist = 0x40 channel 2 -> ao_chanlist = 0x80 channel 3 -> ao_chanlist = 0xc0 The problem is, the usbduxsub_ao_isoc_irq() function uses the 'chan' value from 'ao_chanlist' to access the 'ao_readback' array in the private data. So instead of accessing the array as 0, 1, 2, 3, it accesses it as 0x00, 0x40, 0x80, 0xc0. Fix this by storing the raw channel number in 'ao_chanlist' and doing the bit-shift when creating the command. Fixes: a998a3db530bff80 "staging: comedi: usbdux: cleanup the private data 'outBuffer'" Cc: stable # 3.12 Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Acked-by: Bernd Porr Signed-off-by: Greg Kroah-Hartman

staging: comedi: fix circular locking dependency in comedi_mmap()

2014-04-16T18:41:45+00:00

Mmapping a comedi data buffer with lockdep checking enabled produced the following kernel debug messages: ====================================================== [ INFO: possible circular locking dependency detected ] 3.5.0-rc3-ija1+ #9 Tainted: G C ------------------------------------------------------- comedi_test/4160 is trying to acquire lock: (&dev->mutex#2){+.+.+.}, at: [] comedi_mmap+0x57/0x1d9 [comedi] but task is already holding lock: (&mm->mmap_sem){++++++}, at: [] vm_mmap_pgoff+0x41/0x76 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&mm->mmap_sem){++++++}: [] lock_acquire+0x97/0x105 [] might_fault+0x6d/0x90 [] do_devinfo_ioctl.isra.7+0x11e/0x14c [comedi] [] comedi_unlocked_ioctl+0x256/0xe48 [comedi] [] vfs_ioctl+0x18/0x34 [] do_vfs_ioctl+0x382/0x43c [] sys_ioctl+0x42/0x65 [] system_call_fastpath+0x16/0x1b -> #0 (&dev->mutex#2){+.+.+.}: [] __lock_acquire+0x101d/0x1591 [] lock_acquire+0x97/0x105 [] mutex_lock_nested+0x46/0x2a4 [] comedi_mmap+0x57/0x1d9 [comedi] [] mmap_region+0x281/0x492 [] do_mmap_pgoff+0x26b/0x2a7 [] vm_mmap_pgoff+0x5d/0x76 [] sys_mmap_pgoff+0xc7/0x10d [] sys_mmap+0x16/0x20 [] system_call_fastpath+0x16/0x1b other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&dev->mutex#2); lock(&mm->mmap_sem); lock(&dev->mutex#2); *** DEADLOCK *** To avoid the circular dependency, just try to get the lock in `comedi_mmap()` instead of blocking. Since the comedi device's main mutex is heavily used, do a down-read of its `attach_lock` rwsemaphore instead. Trying to down-read `attach_lock` should only fail if some task has down-write locked it, and that is only done while the comedi device is being attached to or detached from a low-level hardware device. Unfortunately, acquiring the `attach_lock` doesn't prevent another task replacing the comedi data buffer we are trying to mmap. The details of the buffer are held in a `struct comedi_buf_map` and pointed to by `s->async->buf_map` where `s` is the comedi subdevice whose buffer we are trying to map. The `struct comedi_buf_map` is already reference counted with a `struct kref`, so we can stop it being freed prematurely. Modify `comedi_mmap()` to call new function `comedi_buf_map_from_subdev_get()` to read the subdevice's current buffer map pointer and increment its reference instead of accessing `async->buf_map` directly. Call `comedi_buf_map_put()` to decrement the reference once the buffer map structure has been dealt with. (Note that `comedi_buf_map_put()` does nothing if passed a NULL pointer.) `comedi_buf_map_from_subdev_get()` checks the subdevice's buffer map pointer has been set and the buffer map has been initialized enough for `comedi_mmap()` to deal with it (specifically, check the `n_pages` member has been set to a non-zero value). If all is well, the buffer map's reference is incremented and a pointer to it is returned. The comedi subdevice's spin-lock is used to protect the checks. Also use the spin-lock in `__comedi_buf_alloc()` and `__comedi_buf_free()` to protect changes to the subdevice's buffer map structure pointer and the buffer map structure's `n_pages` member. (This checking of `n_pages` is a bit clunky and I [Ian Abbott] plan to deal with it in the future.) Signed-off-by: Ian Abbott Cc: # 3.14.x, 3.15.x Signed-off-by: Greg Kroah-Hartman

staging: comedi: poc: remove obsolete driver

2014-03-20T01:57:01+00:00

The DAC02 board, which is the only board supported by this driver, now has its own comedi driver (dac02). Remove this obsolete driver. Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman

Staging: comedi: Fix line over 80 characters in s626.c

2014-03-19T16:14:22+00:00

Fix checkpatch.pl issues line over 80 characters in s626.c Signed-off-by: Ebru Akagunduz Signed-off-by: Greg Kroah-Hartman

Staging: comedi: Fix missing space after return type in s626.c

2014-03-19T16:14:22+00:00

Fix checkpatch.pl issues with missing space after return type in s626.c Signed-off-by: Ebru Akagunduz Signed-off-by: Greg Kroah-Hartman

Staging: comedi: proc: title block update

2014-03-19T04:41:04+00:00

Follow up patch for "STAGING: comedi: style and checkpatch fixes". Removes the file name in the comment block per suggestions. Signed-off-by: Michael Welling Signed-off-by: Greg Kroah-Hartman

STAGING: comedi: style and checkpatch fixes

2014-03-18T20:04:19+00:00

Updates block comment per Documentation/CodingStyle. Also updated due to checkpatch warnings about qouted string after Lindent modified the spacing slightly. Signed-off-by: Michael Welling Signed-off-by: Greg Kroah-Hartman

staging: comedi: das6402: rewrite broken driver

2014-03-17T21:20:10+00:00

This driver is _really_ broken. It initializes an analog input subdevice that only has a (*cancel) function. It also does a request_irq() to hookup an interrupt handler using it->options[0] as the IRQ. This option is actually the base address of the I/O region used by the board. If the interrupt handler actually did get hooked up, the rest of the code assumes that IRQ 10 is being used. Rewrite the driver to properly support the hardware. The DAS6402-12/16 boards have 64 single-ended / 32 differential analog inputs, 2 analog outputs, 8 digital inputs, and 8 digital outputs. Add proper support for these subdevices. Stub in the analog input async command support. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

staging: comedi: rti802: update the MODULE_DESCRIPTION

2014-03-17T21:20:10+00:00

Change the generic MODULE_DESCRIPTION text to something more specific for this driver. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman