staging: fsl-mc: fix asymmetry in destroy of mc_io

An mc_io represents a mapped MC portal.  Previously, an mc_io was
created for the root dprc in fsl_mc_bus_probe() and for child dprcs
in dprc_probe().  But the free of that data structure happened in the
general bus remove callback.  This asymmetry resulted in some bugs due
to unwanted destroys of mc_io object in some scenarios (e.g. vfio).

Fix this bug by making things symmetric-- mc_io created in
fsl_mc_bus_probe() is freed in fsl_mc_bus_remove().  The mc_io created
in dprc_probe() is freed in dprc_remove().

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
[Stuart: added check for root dprc and reworded commit message]
Signed-off-by: Stuart Yoder <stuart.yoder@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Bharat Bhushan 2016-06-22 16:40:48 -05:00 committed by Greg Kroah-Hartman
parent fde867d308
commit f93627146f
2 changed files with 9 additions and 4 deletions

View File

@ -801,6 +801,11 @@ static int dprc_remove(struct fsl_mc_device *mc_dev)
dev_set_msi_domain(&mc_dev->dev, NULL);
}
if (!fsl_mc_is_root_dprc(&mc_dev->dev)) {
fsl_destroy_mc_io(mc_dev->mc_io);
mc_dev->mc_io = NULL;
}
dev_info(&mc_dev->dev, "DPRC device unbound from driver");
return 0;
}

View File

@ -579,10 +579,6 @@ void fsl_mc_device_remove(struct fsl_mc_device *mc_dev)
if (strcmp(mc_dev->obj_desc.type, "dprc") == 0) {
mc_bus = to_fsl_mc_bus(mc_dev);
if (mc_dev->mc_io) {
fsl_destroy_mc_io(mc_dev->mc_io);
mc_dev->mc_io = NULL;
}
if (fsl_mc_is_root_dprc(&mc_dev->dev)) {
if (atomic_read(&root_dprc_count) > 0)
@ -810,6 +806,10 @@ static int fsl_mc_bus_remove(struct platform_device *pdev)
return -EINVAL;
fsl_mc_device_remove(mc->root_mc_bus_dev);
fsl_destroy_mc_io(mc->root_mc_bus_dev->mc_io);
mc->root_mc_bus_dev->mc_io = NULL;
dev_info(&pdev->dev, "Root MC bus device removed");
return 0;
}