diff options
| author | Cornelia Huck <cornelia.huck@de.ibm.com> | 2006-07-12 16:39:50 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2006-07-12 16:39:50 +0200 |
| commit | 6ab4879a0d074c938fd17dba141dce042fc17bee (patch) | |
| tree | 62e413692d4c55ae322c3201c36ded4808806cb5 /drivers/s390/cio/css.c | |
| parent | 63f4f9e1281ea9b9a2304bd13d657ba9d401c9a7 (diff) | |
[S390] subchannel register/unregister mutex.
Add a reg_mutex to prevent unregistering a subchannel before it has been
registered. Since 2.6.17, we've seen oopses in kslowcrw when a device is
found to be not operational during sense id when doing initial device
recognition; it is not clear yet why that particular problem was not (yet)
observed with earlier kernels...
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio/css.c')
| -rw-r--r-- | drivers/s390/cio/css.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 1d3be80797f..a09deea5d68 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -108,6 +108,24 @@ css_subchannel_release(struct device *dev) extern int css_get_ssd_info(struct subchannel *sch); + +int css_sch_device_register(struct subchannel *sch) +{ + int ret; + + mutex_lock(&sch->reg_mutex); + ret = device_register(&sch->dev); + mutex_unlock(&sch->reg_mutex); + return ret; +} + +void css_sch_device_unregister(struct subchannel *sch) +{ + mutex_lock(&sch->reg_mutex); + device_unregister(&sch->dev); + mutex_unlock(&sch->reg_mutex); +} + static int css_register_subchannel(struct subchannel *sch) { @@ -119,7 +137,7 @@ css_register_subchannel(struct subchannel *sch) sch->dev.release = &css_subchannel_release; /* make it known to the system */ - ret = device_register(&sch->dev); + ret = css_sch_device_register(sch); if (ret) printk (KERN_WARNING "%s: could not register %s\n", __func__, sch->dev.bus_id); @@ -250,7 +268,7 @@ css_evaluate_subchannel(struct subchannel_id schid, int slow) * The device will be killed automatically. */ cio_disable_subchannel(sch); - device_unregister(&sch->dev); + css_sch_device_unregister(sch); /* Reset intparm to zeroes. */ sch->schib.pmcw.intparm = 0; cio_modify(sch); @@ -264,7 +282,7 @@ css_evaluate_subchannel(struct subchannel_id schid, int slow) * away in any case. */ if (!disc) { - device_unregister(&sch->dev); + css_sch_device_unregister(sch); /* Reset intparm to zeroes. */ sch->schib.pmcw.intparm = 0; cio_modify(sch); |