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path: root/drivers/hwtracing/intel_th/gth.c
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2015-10-16intel_th: Check for NULL instead of ERR_PTRDan Carpenter
devm_ioremap() returns NULL on error, it doesn't return an ERR_PTR, which is what the current code does. This patch corrects these checks. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04intel_th: Add Global Trace Hub driverAlexander Shishkin
Global Trace Hub (GTH) is the central component of Intel TH architecture; it carries out switching between the trace sources and trace outputs, can enable/disable tracing, perform STP encoding, internal buffering, control backpressure from outputs to sources and so on. This property is also reflected in the software model; GTH (switch) driver is required for the other subdevices to probe, because it matches trace output devices against its output ports and configures them accordingly. It also implements an interface for output ports to request trace enabling or disabling and a few other useful things. For userspace, it provides an attribute group "masters", which allows configuration of per-master trace output destinations for up to master 255 and "256+" meaning "masters 256 and above". It also provides an attribute group to discover and configure some of the parameters of its output ports, called "outputs". Via these the user can set up data retention policy for an individual output port or check if it is in reset state. Signed-off-by: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>