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author | Gwendal Grignou <gwendal@chromium.org> | 2017-03-03 09:00:09 -0800 |
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committer | Tejun Heo <tj@kernel.org> | 2017-03-06 15:24:48 -0500 |
commit | d85fc67dd11e9a32966140677d4d6429ca540b25 (patch) | |
tree | faf40259eb99fc42941b828a7870fbff6f012146 /drivers/ata | |
parent | c1ae3cfa0e89fa1a7ecc4c99031f5e9ae99d9201 (diff) | |
download | lwn-d85fc67dd11e9a32966140677d4d6429ca540b25.tar.gz lwn-d85fc67dd11e9a32966140677d4d6429ca540b25.zip |
libata: transport: Remove circular dependency at free time
Without this patch, failed probe would not free resources like irq.
ata port tdev object currently hold a reference to the ata port
object. Therefore the ata port object release function will not get
called until the ata_tport_release is called. But that would never
happen, releasing the last reference of ata port dev is done by
scsi_host_release, which is called by ata_host_release when the ata
port object is released.
The ata device objects actually do not need to explicitly hold a
reference to their real counterpart, given the transport objects are
the children of these objects and device_add() is call for each child.
We know the parent will not be deleted until we call the child's
device_del().
Reported-by: Matthew Whitehead <tedheadster@gmail.com>
Tested-by: Matthew Whitehead <tedheadster@gmail.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/ata')
-rw-r--r-- | drivers/ata/libata-transport.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c index 46698232e6bf..19e6e539a061 100644 --- a/drivers/ata/libata-transport.c +++ b/drivers/ata/libata-transport.c @@ -224,7 +224,6 @@ static DECLARE_TRANSPORT_CLASS(ata_port_class, static void ata_tport_release(struct device *dev) { - put_device(dev->parent); } /** @@ -284,7 +283,7 @@ int ata_tport_add(struct device *parent, device_initialize(dev); dev->type = &ata_port_type; - dev->parent = get_device(parent); + dev->parent = parent; dev->release = ata_tport_release; dev_set_name(dev, "ata%d", ap->print_id); transport_setup_device(dev); @@ -348,7 +347,6 @@ static DECLARE_TRANSPORT_CLASS(ata_link_class, static void ata_tlink_release(struct device *dev) { - put_device(dev->parent); } /** @@ -410,7 +408,7 @@ int ata_tlink_add(struct ata_link *link) int error; device_initialize(dev); - dev->parent = get_device(&ap->tdev); + dev->parent = &ap->tdev; dev->release = ata_tlink_release; if (ata_is_host_link(link)) dev_set_name(dev, "link%d", ap->print_id); @@ -589,7 +587,6 @@ static DECLARE_TRANSPORT_CLASS(ata_dev_class, static void ata_tdev_release(struct device *dev) { - put_device(dev->parent); } /** @@ -662,7 +659,7 @@ static int ata_tdev_add(struct ata_device *ata_dev) int error; device_initialize(dev); - dev->parent = get_device(&link->tdev); + dev->parent = &link->tdev; dev->release = ata_tdev_release; if (ata_is_host_link(link)) dev_set_name(dev, "dev%d.%d", ap->print_id,ata_dev->devno); |