4.19-stable review patch. If anyone has any objections, please let me know.
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From: Alexander Usyskin alexander.usyskin@intel.com
commit b5958faa34e2f99f3475ad89c52d98dfea079d33 upstream.
Fix unbalanced module reference counting during internal reset, which prevents the drivers unloading. Tracking mei_me/txe modules on mei client bus via mei_cldev_enable/disable is error prone due to possible internal reset flow, where clients are disconnected underneath. Moving reference counting to probe and release of mei bus client driver solves this issue in simplest way, as each client provides only a single connection to a client bus driver.
Cc: stable@vger.kernel.org Signed-off-by: Alexander Usyskin alexander.usyskin@intel.com Signed-off-by: Tomas Winkler tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/misc/mei/bus.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-)
--- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -541,17 +541,9 @@ int mei_cldev_enable(struct mei_cl_devic goto out; }
- if (!mei_cl_bus_module_get(cldev)) { - dev_err(&cldev->dev, "get hw module failed"); - ret = -ENODEV; - goto out; - } - ret = mei_cl_connect(cl, cldev->me_cl, NULL); - if (ret < 0) { + if (ret < 0) dev_err(&cldev->dev, "cannot connect\n"); - mei_cl_bus_module_put(cldev); - }
out: mutex_unlock(&bus->device_lock); @@ -614,7 +606,6 @@ int mei_cldev_disable(struct mei_cl_devi if (err < 0) dev_err(bus->dev, "Could not disconnect from the ME client\n");
- mei_cl_bus_module_put(cldev); out: /* Flush queues and remove any pending read */ mei_cl_flush_queues(cl, NULL); @@ -725,9 +716,16 @@ static int mei_cl_device_probe(struct de if (!id) return -ENODEV;
+ if (!mei_cl_bus_module_get(cldev)) { + dev_err(&cldev->dev, "get hw module failed"); + return -ENODEV; + } + ret = cldrv->probe(cldev, id); - if (ret) + if (ret) { + mei_cl_bus_module_put(cldev); return ret; + }
__module_get(THIS_MODULE); return 0; @@ -755,6 +753,7 @@ static int mei_cl_device_remove(struct d
mei_cldev_unregister_callbacks(cldev);
+ mei_cl_bus_module_put(cldev); module_put(THIS_MODULE); dev->driver = NULL; return ret;