Re: 2.6.21-rc4-mm1

From: Cornelia Huck
Date: Fri Mar 23 2007 - 06:08:54 EST


On Thu, 22 Mar 2007 13:55:51 -0500,
Larry Finger <larry.finger@xxxxxxxxxxxx> wrote:

> Cornelia Huck wrote:
> > On Thu, 22 Mar 2007 07:23:06 -0500,
> >
> > This would indicate that dev_uevent had been called. But how could
> > kobject_uevent then return an error without moaning about an uevent()
> > error code? Maybe the following debug patch could shed some light on
> > this (all moaning is prefixed with kobject_uevent_env, so it should be
> > easy to spot)...
>
> I applied the debug patch, but I don't see any error codes being returned. This time I also got the
> General Protection Faults. An excerpt of the log is attached.

Hm, I think I have an idea about what happened.

The firmware class tried to suppress the first KOBJ_ADD uevent by
returning -ENODEV in firmware_uevent if FW_STATUS_READY was not set.
This only worked as long as the return code of kobject_uevent was not
checked in device_add. hack-to-make-wireless-work.patch made that first
uevent return successfully, but this possible triggered some udev rule
too early, leading to firmware load failures.

The following (completely untested) patch uses uevent_suppress to stop
the uevent from being generated during device_add. Does this work for
you?

---
drivers/base/firmware_class.c | 2 ++
1 file changed, 2 insertions(+)

--- linux-2.6.orig/drivers/base/firmware_class.c
+++ linux-2.6/drivers/base/firmware_class.c
@@ -333,6 +333,7 @@ static int fw_register_device(struct dev
f_dev->parent = device;
f_dev->class = &firmware_class;
dev_set_drvdata(f_dev, fw_priv);
+ f_dev->uevent_suppress = 1;
retval = device_register(f_dev);
if (retval) {
printk(KERN_ERR "%s: device_register failed\n",
@@ -385,6 +386,7 @@ static int fw_setup_device(struct firmwa
set_bit(FW_STATUS_READY, &fw_priv->status);
else
set_bit(FW_STATUS_READY_NOHOTPLUG, &fw_priv->status);
+ f_dev->uevent_suppress = 0;
*dev_p = f_dev;
goto out;

-
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