On Fri, Aug 21, 2020 at 11:44:41AM +0800, Tingwei Zhang wrote: > CTI device is enabled when associated coresight device is enabled. > Increase the module and device reference count for CTI device > when it's enabled. This can prevent CTI device be removed or > module be unloaded when CTI device is enabled by an active trace > session. > > Signed-off-by: Mike Leach <[email protected]> > Signed-off-by: Tingwei Zhang <[email protected]> > ---
Reviewed-by: Mathieu Poirier <[email protected]> > drivers/hwtracing/coresight/coresight.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight.c > b/drivers/hwtracing/coresight/coresight.c > index d354fd57474e..6c9f6930b8b8 100644 > --- a/drivers/hwtracing/coresight/coresight.c > +++ b/drivers/hwtracing/coresight/coresight.c > @@ -241,19 +241,30 @@ coresight_control_assoc_ectdev(struct coresight_device > *csdev, bool enable) > { > int ect_ret = 0; > struct coresight_device *ect_csdev = csdev->ect_dev; > + struct module *mod; > > if (!ect_csdev) > return 0; > if ((!ect_ops(ect_csdev)->enable) || (!ect_ops(ect_csdev)->disable)) > return 0; > > + mod = ect_csdev->dev.parent->driver->owner; > if (enable) { > - ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); > - if (!ect_ret) > - csdev->ect_enabled = true; > + if (try_module_get(mod)) { > + ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); > + if (ect_ret) { > + module_put(mod); > + } else { > + get_device(ect_csdev->dev.parent); > + csdev->ect_enabled = true; > + } > + } else > + ect_ret = -ENODEV; > } else { > if (csdev->ect_enabled) { > ect_ret = ect_ops(ect_csdev)->disable(ect_csdev); > + put_device(ect_csdev->dev.parent); > + module_put(mod); > csdev->ect_enabled = false; > } > } > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
