kernel/linux.git/drivers/iio/industrialio-buffer.c, branch linux-4.4.y

iio: buffer: Fix demux update

2021-01-23T14:36:56+00:00

commit 19ef7b70ca9487773c29b449adf0c70f540a0aab upstream When updating the buffer demux, we will skip a scan element from the device in the case `in_ind != out_ind` and we enter the while loop. in_ind should only be refreshed with `find_next_bit()` in the end of the loop. Note, to cause problems we need a situation where we are skippig over an element (channel not enabled) that happens to not have the same size as the next element. Whilst this is a possible situation we haven't actually identified any cases in mainline where it happens as most drivers have consistent channel storage sizes with the exception of the timestamp which is the last element and hence never skipped over. Fixes: 5ada4ea9be16 ("staging:iio: add demux optionally to path from device to buffer") Signed-off-by: Nuno Sá Link: https://lore.kernel.org/r/20201112144323.28887-1-nuno.sa@analog.com Cc: Signed-off-by: Jonathan Cameron [sudip: adjust context] Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

iio: buffer: align the size of scan bytes to size of the largest element

2020-01-29T09:21:52+00:00

commit 883f616530692d81cb70f8a32d85c0d2afc05f69 upstream. Previous versions of `iio_compute_scan_bytes` only aligned each element to its own length (i.e. its own natural alignment). Because multiple consecutive sets of scan elements are buffered this does not work in case the computed scan bytes do not align with the natural alignment of the first scan element in the set. This commit fixes this by aligning the scan bytes to the natural alignment of the largest scan element in the set. Fixes: 959d2952d124 ("staging:iio: make iio_sw_buffer_preenable much more general.") Signed-off-by: Lars Möllendorf Reviewed-by: Lars-Peter Clausen Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman

iio: buffer: check if a buffer has been set up when poll is called

2018-02-28T09:17:22+00:00

commit 4cd140bda6494543f1c1b0ccceceaa44b676eef6 upstream. If no iio buffer has been set up and poll is called return 0. Without this check there will be a null pointer dereference when calling poll on a iio driver without an iio buffer. Cc: stable@vger.kernel.org Signed-off-by: Stefan Windfeldt-Prytz Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman

iio: ensure ret is initialized to zero before entering do loop

2016-09-24T08:07:38+00:00

commit 5dba4b14bafe801083d01e1f400816df7e5a8f2e upstream. A recent fix to iio_buffer_read_first_n_outer removed ret from being set by a return from wait_event_interruptible and also added a continue in a loop which causes the variable ret to not be set when it reaches the end of the loop. Fix this by initializing ret to zero. Also remove extraneous white space at the end of the loop. Fixes: fcf68f3c0bb2a5 ("fix sched WARNING "do not call blocking ops when !TASK_RUNNING") Signed-off-by: Colin Ian King Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman

iio: fix sched WARNING "do not call blocking ops when !TASK_RUNNING"

2016-09-07T06:32:41+00:00

commit fcf68f3c0bb2a541aa47a2a38b8939edf84fd529 upstream. When using CONFIG_DEBUG_ATOMIC_SLEEP, the scheduler nicely points out that we're calling sleeping primitives within the wait_event loop, which means we might clobber the task state: [ 10.831289] do not call blocking ops when !TASK_RUNNING; state=1 set at [] [ 10.845531] ------------[ cut here ]------------ [ 10.850161] WARNING: at kernel/sched/core.c:7630 ... [ 12.164333] ---[ end trace 45409966a9a76438 ]--- [ 12.168942] Call trace: [ 12.171391] [] __might_sleep+0x64/0x90 [ 12.176699] [] mutex_lock_nested+0x50/0x3fc [ 12.182440] [] iio_kfifo_buf_data_available+0x28/0x4c [ 12.189043] [] iio_buffer_ready+0x60/0xe0 [ 12.194608] [] iio_buffer_read_first_n_outer+0x108/0x1a8 [ 12.201474] [] __vfs_read+0x58/0x114 [ 12.206606] [] vfs_read+0x94/0x118 [ 12.211564] [] SyS_read+0x64/0xb4 [ 12.216436] [] el0_svc_naked+0x24/0x28 To avoid this, we should (a la https://lwn.net/Articles/628628/) use the wait_woken() function, which avoids the nested sleeping while still handling races between waiting / wake-events. Signed-off-by: Brian Norris Reviewed-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman

iio: fix some warning messages

2015-11-21T16:00:05+00:00

WARN_ON() only takes a condition argument. I have changed these to WARN() instead. Signed-off-by: Dan Carpenter Cc: Signed-off-by: Jonathan Cameron

iio: industrialio-buffer: Fix iio_buffer_poll return value

2015-08-12T18:26:34+00:00

Change return value to 0 if no device is bound since unsigned int cannot support negative error codes. Fixes: f18e7a068 ("iio: Return -ENODEV for file operations if the device has been unregistered") Signed-off-by: Cristina Opriceana Cc: Signed-off-by: Jonathan Cameron

iio: buffer: Fix kernel docs warnings

2015-08-02T17:27:09+00:00

Fix kernel docs for structures and functions in order to remove some warnings when the documentation gets generated. Signed-off-by: Cristina Opriceana Signed-off-by: Jonathan Cameron

iio: allow userspace to flush the hwfifo with non-blocking reads

2015-06-21T13:51:13+00:00

This patch changes the semantics of non-blocking reads so that a hardware fifo flush is triggered if the available data in the device buffer is less then the requested size. This allows userspace to accurately generate hardware fifo flushes, by doing a non-blocking read with a size greater then the sum of the device buffer and hardware fifo size. Signed-off-by: Octavian Purdila Reviewed-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron

iio: Require strict scan mask matching in hardware mode

2015-06-01T10:34:54+00:00

In hardware mode we can not use the software demuxer, this means that the selected scan mask needs to match one of the available scan masks exactly. It also means that all attached buffers need to use the same scan mask. Given that when operating in hardware mode there is typically only a single buffer attached to the device this not an issue. Add a sanity check to make sure that only a single buffer is attached in hardware mode nevertheless. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron