Re: 2.6.11-rc4-mm1: something is wrong with swsusp powerdown

[Pavel Machek <pavel@suse.cz>]

Hi!

> btw, suspend is a bit messy.  The disk spins down.  Then up.  Then down
> again.  And:

Yes, this is going to be properly solved by switching pm_message_t to
struct (preview patch attached, EVENT will become .event, this is just
for me). I could do some hack to make disk not go up-down-up (and will
need to do it for suse9.3, anyway), but I do not think that would
belong to mainline.

> Powering off system
> Debug: sleeping function called from invalid context at include/linux/rwsem.h:66
> in_atomic():0, irqs_disabled():1                                                
>  [<c010318d>] dump_stack+0x19/0x20
>  [<c0111731>] __might_sleep+0x91/0x9c
>  [<c0285872>] device_shutdown+0x16/0x82
>  [<c012aa97>] power_down+0x47/0x74     
>  [<c012ac5a>] pm_suspend_disk+0x5a/0x74
>  [<c01292ea>] enter_state+0x2e/0x70    
>  [<c0129336>] software_suspend+0xa/0x10
>  [<c024a8a7>] acpi_system_write_sleep+0x73/0x98
>  [<c0149f1b>] vfs_write+0xaf/0x118             
>  [<c014a028>] sys_write+0x3c/0x68 
>  [<c0102c05>] sysenter_past_esp+0x52/0x75
> Synchronizing SCSI cache for disk sda:   
> Shutdown: hda                          
> acpi_power_off called

Hmm, device_shutdown is confused. Should it be called with interrupts
enabled or disabled? It uses rwsem, that suggests interrupts enabled,
but I do not think sysdev_shutdown with enabled interrupts is good
idea (and comment suggests it should be called with interrupts disabled).

								Pavel

/**
 * We handle system devices differently - we suspend and shut them
 * down last and resume them first. That way, we don't do anything
stupid like
 * shutting down the interrupt controller before any devices..
 *
 * Note that there are not different stages for power management calls
-
 * they only get one called once when interrupts are disabled.
 */

extern int sysdev_shutdown(void);

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
        struct device * dev;

        down_write(&devices_subsys.rwsem);
        list_for_each_entry_reverse(dev, &devices_subsys.kset.list, kobj.entry) {
                pr_debug("shutting down %s: ", dev->bus_id);
                if (dev->driver && dev->driver->shutdown) {
                        pr_debug("Ok\n");
                        dev->driver->shutdown(dev);
                } else
                        pr_debug("Ignored.\n");
        }
        up_write(&devices_subsys.rwsem);

        sysdev_shutdown();
}



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