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authorAshutosh Dixit <ashutosh.dixit@intel.com>2015-11-17 15:55:37 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-07 22:53:40 -0800
commitf38e87e8c8d326ec6cddfc3f286b605d996a52a3 (patch)
tree53e4b89cefab1d0183f7f380668d8e6862426cd9 /drivers/misc/mic
parent3f040887a8be0c28a099a9106bc29443d4f79a7e (diff)
downloadop-kernel-dev-f38e87e8c8d326ec6cddfc3f286b605d996a52a3.zip
op-kernel-dev-f38e87e8c8d326ec6cddfc3f286b605d996a52a3.tar.gz
misc: mic: Fix crash when MIC reset is invoked in RESET_FAILED state
This patch fixes the following crash seen when MIC reset is invoked in RESET_FAILED state due to device_del being called a second time on an already deleted device: [<ffffffff813b2295>] device_del+0x45/0x1d0 [<ffffffff813b243e>] device_unregister+0x1e/0x60 [<ffffffffa040f1c2>] scif_unregister_device+0x12/0x20 [scif_bus] [<ffffffffa042f75a>] cosm_stop+0xaa/0xe0 [mic_cosm] [<ffffffffa042f844>] cosm_reset_trigger_work+0x14/0x20 [mic_cosm] The fix consists in realizing that because cosm_reset changes the state to MIC_RESETTING, cosm_stop needs the previous state, before it changed to MIC_RESETTING, to decide whether a hw_ops->stop had previously been issued. This is now provided in a new cosm_device member cdev->prev_state. Reviewed-by: Sudeep Dutt <sudeep.dutt@intel.com> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/mic')
-rw-r--r--drivers/misc/mic/bus/cosm_bus.h2
-rw-r--r--drivers/misc/mic/cosm/cosm_main.c13
2 files changed, 11 insertions, 4 deletions
diff --git a/drivers/misc/mic/bus/cosm_bus.h b/drivers/misc/mic/bus/cosm_bus.h
index f7c57f2..8b63418 100644
--- a/drivers/misc/mic/bus/cosm_bus.h
+++ b/drivers/misc/mic/bus/cosm_bus.h
@@ -30,6 +30,7 @@
* @attr_group: Pointer to list of sysfs attribute groups.
* @sdev: Device for sysfs entries.
* @state: MIC state.
+ * @prev_state: MIC state previous to MIC_RESETTING
* @shutdown_status: MIC status reported by card for shutdown/crashes.
* @shutdown_status_int: Internal shutdown status maintained by the driver
* @cosm_mutex: Mutex for synchronizing access to data structures.
@@ -55,6 +56,7 @@ struct cosm_device {
const struct attribute_group **attr_group;
struct device *sdev;
u8 state;
+ u8 prev_state;
u8 shutdown_status;
u8 shutdown_status_int;
struct mutex cosm_mutex;
diff --git a/drivers/misc/mic/cosm/cosm_main.c b/drivers/misc/mic/cosm/cosm_main.c
index 4b4b356..7005cb1 100644
--- a/drivers/misc/mic/cosm/cosm_main.c
+++ b/drivers/misc/mic/cosm/cosm_main.c
@@ -153,8 +153,10 @@ void cosm_stop(struct cosm_device *cdev, bool force)
* stop(..) calls device_unregister and will crash the system if
* called multiple times.
*/
- bool call_hw_ops = cdev->state != MIC_RESET_FAILED &&
- cdev->state != MIC_READY;
+ u8 state = cdev->state == MIC_RESETTING ?
+ cdev->prev_state : cdev->state;
+ bool call_hw_ops = state != MIC_RESET_FAILED &&
+ state != MIC_READY;
if (cdev->state != MIC_RESETTING)
cosm_set_state(cdev, MIC_RESETTING);
@@ -195,8 +197,11 @@ int cosm_reset(struct cosm_device *cdev)
mutex_lock(&cdev->cosm_mutex);
if (cdev->state != MIC_READY) {
- cosm_set_state(cdev, MIC_RESETTING);
- schedule_work(&cdev->reset_trigger_work);
+ if (cdev->state != MIC_RESETTING) {
+ cdev->prev_state = cdev->state;
+ cosm_set_state(cdev, MIC_RESETTING);
+ schedule_work(&cdev->reset_trigger_work);
+ }
} else {
dev_err(&cdev->dev, "%s %d MIC is READY\n", __func__, __LINE__);
rc = -EINVAL;
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