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* Problems with arch/i386/kernel/apm.c
@ 2001-06-11 17:57 Jeff Golds
  2001-06-11 18:11 ` Jeff Garzik
  2001-06-11 19:37 ` John Fremlin
  0 siblings, 2 replies; 6+ messages in thread
From: Jeff Golds @ 2001-06-11 17:57 UTC (permalink / raw)
  To: linux-kernel

Hi folks,

I've been debugging a problem I've been having with APM.  When I
initiate an "apm --suspend" command, my Tulip card doesn't work
anymore.  However, if I then execute "ifconfig eth0 down ; ifconfig eth0
up" then everything is fine again.

I initially thought the problem was on the Tulip driver side, so I
instrumented the code and found that the driver was correctly processing
incoming and outgoing packets, but it appeared the tx ring was out of
sync with the driver.

Since the tulip_suspend, and tulip_resume functions were basically doing
the same thing as what "ifconfig eth0 down/up" (WRT to the Tulip driver)
I began to look elsewhere.  I think I've tracked the problem down to the
following code:

static int suspend(void)
{
        int             err;
        struct apm_user *as;
 
	...
        cli();
        err = apm_set_power_state(APM_STATE_SUSPEND);
	...
        send_event(APM_NORMAL_RESUME);
        sti();
	...
        return err;
}                                                                                       

So it seems that drivers are suspended before the cli(), yet they are
resumed before the sti().  It seems to me that the sti() should come
before apm::send_event(APM_NORMAL_RESUME), and, in fact, if I swap the
two, Tulip survives suspend/resume

Please let me know if this is correct, I can provide a simple patch if
needed.  What I am really desiring to know is if there are any devices
that depend on the apm::send_event(APM_NORMAL_RESUME) happening while
interrupts are disabled.

-Jeff

-- 
Jeff Golds
Sr. Software Engineer
jgolds@resilience.com

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2001-06-14  8:20 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2001-06-11 17:57 Problems with arch/i386/kernel/apm.c Jeff Golds
2001-06-11 18:11 ` Jeff Garzik
2001-06-11 18:42   ` Alan Cox
2001-06-12 23:48     ` Patrick Mochel
2001-06-14  8:18       ` Alan Cox
2001-06-11 19:37 ` John Fremlin

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