Commit Graph

13 Commits

Author SHA1 Message Date
Alexander Shishkin e609ccef52 intel_th: Don't leak module refcount on failure to activate
Output 'activation' may fail for the reasons of the output driver,
for example, if msc's buffer is not allocated. We forget, however,
to drop the module reference in this case. So each attempt at
activation in this case leaks a reference, preventing the module
from ever unloading.

This patch adds the missing module_put() in the activation error
path.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: stable@vger.kernel.org # v4.8+
2017-03-15 14:54:57 +02:00
Alexander Shishkin c49a75910c intel_th: Support Host Debugger mode of operation
This patch adds a 'host_mode' module option to enable host-driven
operational mode in the driver. In this mode, the driver does not
perform trace configuration or enable trace capture, but still
provides all the means necessary for software trace sources to
write their data to the Trace Hub. This means that the debug host
takes care of all the configuration and enabling and we do not
interfere.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-11-18 17:07:54 +02:00
Alexander Shishkin 77c98b28ee intel_th: Constify subdevices
The subdevice array consists of immutable objects, make them const.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-11-18 17:07:18 +02:00
Greg Kroah-Hartman 80f7631963 intel_th: Fixes -stable
These are:
  * a fix for a modprobe time deadlock
  * a new PCI ID for Kaby Lake PCH-H
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Merge tag 'stm-for-greg-20160714' of git://git.kernel.org/pub/scm/linux/kernel/git/ash/stm into char-misc-next

Alexander writes:

intel_th: Fixes -t://git.kernel.org/pub/scm/linux/kernel/git/ash/stm.git
tags/stm-for-greg-20160714
stable

These are:
 * a fix for a modprobe time deadlock
 * a new PCI ID for Kaby Lake PCH-H
2016-07-15 14:19:11 +09:00
Alexander Shishkin a36aa80f3c intel_th: Fix a deadlock in modprobing
Driver initialization tries to request a hub (GTH) driver module from
its probe callback, resulting in a deadlock.

This patch solves the problem by adding a deferred work for requesting
the hub module.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: <stable@vger.kernel.org> # 4.4.x-
2016-07-14 13:02:39 +03:00
Alexander Shishkin 142dfeb202 intel_th: Add runtime power management handling
Currently, an Intel TH (pci) device will be always active, because the
devices on the 'intel_th' bus don't implement runtime pm to track their
usage.

To address this, this patch adds runtime pm support to the 'intel_th'
bus and some additional bits for the hub. The 'output' type device is
in use while a capture is active; the 'source' type device (STH) relies
on its child stm class device for runtime pm tracking.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-07-01 11:01:01 +03:00
Alexander Shishkin e2ea295baf intel_th: Hold output driver module reference while capture is active
Right now it's possible to unload the output subdevice's driver while
the capture to this output is active. Prevent this by holding the
output driver's module reference.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 17:41:25 +03:00
Alexander Shishkin f18a9531f6 intel_th: Fix activating a subdevice without a driver
If output subdevice driver is not loaded, activating it will try to
call its ->activate method and crash. Fix this by explicitly checking
for the driver.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:58 +03:00
Alexander Shishkin b5edbf1ea3 intel_th: Allow subdevice drivers to bring in own attribute groups
Some subdevices (MSU, PTI) need to register their own driver-specific
attribute groups. Provide a way for those to pass their attribute
groups to the core driver in their driver structure so that the
core can take care of creating and removing them.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:56 +03:00
Alexander Shishkin 14136e368f intel_th: Use real device index in the node names
Most of the intel_th core supports multiple co-existing TH devices,
except for output device nodes, where intel_th device id is hardcoded
to be zero.

Fix this by fetching the actual intel_th device id from the parent
device's drvdata.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin d7b1787161 intel_th: Set root device's drvdata early
Already during the subdevice initialization time, devices will need
to reference Intel TH controller descriptor structure.

This patch moves setting the drvdata from the pci glue to intel_th
core, before subdevices are populated.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin 4d02ceff32 intel_th: Update scratchpad bits according to enabled output activity
Intel TH implements a scratchpad register to indicate to the firmware
and external debuggers what trace configuration is enabled so that
everybody plays nicely together. The register is a bit field and the
bit assignment convention is described in the developer's manual.

This patch enables the driver to automatically set scratchpad register
bits according to the output configuration that's enabled.

Based on work by Yann Fouassier.

Signed-off-by: Yann Fouassier <yann.fouassier@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin 39f4034693 intel_th: Add driver infrastructure for Intel(R) Trace Hub devices
Intel(R) Trace Hub (TH) is a set of hardware blocks (subdevices) that
produce, switch and output trace data from multiple hardware and
software sources over several types of trace output ports encoded
in System Trace Protocol (MIPI STPv2) and is intended to perform
full system debugging.

For these subdevices, we create a bus, where they can be discovered
and configured by userspace software.

This patch creates this bus infrastructure, three types of devices
(source, output, switch), resource allocation, some callback mechanisms
to facilitate communication between the subdevices' drivers and some
common sysfs attributes.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 20:28:58 +01:00