OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

intel_th: gth: Handle host mode correctly 

When detecting host debugger mode either though a module option or via
the scratchpad register, do not export any configuration or capture
related attributes to userspace and refuse attempts by the output drivers
to configure output ports.

This way, GTH can still act as a hub and ensure that the other components
that rely on its presence continue to function properly, namely the
source devices.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
This commit is contained in:
Alexander Shishkin 2016-09-19 17:27:45 +03:00
parent c49a75910c
commit d4f5f545da
1 changed files with 24 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/hwtracing/intel_th/gth.c
View File

@ -564,6 +564,9 @@ static int intel_th_gth_assign(struct intel_th_device *thdev,
struct gth_device *gth = dev_get_drvdata(&thdev->dev);
int i, id;
if (thdev->host_mode)
return -EBUSY;
if (othdev->type != INTEL_TH_OUTPUT)
return -EINVAL;
@ -600,6 +603,9 @@ static void intel_th_gth_unassign(struct intel_th_device *thdev,
struct gth_device *gth = dev_get_drvdata(&thdev->dev);
int port = othdev->output.port;
if (thdev->host_mode)
return;
spin_lock(&gth->gth_lock);
othdev->output.port = -1;
othdev->output.active = false;
@ -654,9 +660,24 @@ static int intel_th_gth_probe(struct intel_th_device *thdev)
gth->base = base;
spin_lock_init(&gth->gth_lock);
/*
* Host mode can be signalled via SW means or via SCRPD_DEBUGGER_IN_USE
* bit. Either way, don't reset HW in this case, and don't export any
* capture configuration attributes. Also, refuse to assign output
* drivers to ports, see intel_th_gth_assign().
*/
if (thdev->host_mode)
goto done;
ret = intel_th_gth_reset(gth);
if (ret)
return ret;
if (ret) {
if (ret != -EBUSY)
return ret;
thdev->host_mode = true;
goto done;
}
for (i = 0; i < TH_CONFIGURABLE_MASTERS + 1; i++)
gth->master[i] = -1;
@ -677,6 +698,7 @@ static int intel_th_gth_probe(struct intel_th_device *thdev)
return -ENOMEM;
}
done:
dev_set_drvdata(dev, gth);
return 0;