X-Envelope-To: <djgpp AT delorie DOT com>
From: "Javier Calleja" <dismuntel AT apdo DOT com>
To: "djgpp" <djgpp AT delorie DOT com>
Subject: Does the 'go32_dpmi_allocate_iret_wrapper' do the 'STI' instruction?
Date: Mon, 28 Jun 1999 10:07:05 +0200
Message-ID: <01bec13d$366afe60$0720a8c0@salmon.ctv.es>
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Reply-To: djgpp AT delorie DOT com

Hi world:

  I have wrote a C hardware interrupt handler and I have used the
'go32_dpmi_allocate_iret_wrapper'. I have read that
"... where the CPU's interrupt is virtualizad, IRET may not restore the
interrupt flag. Therefore clients should execute a STI instruction or else
interrupts remain disabled."

  Before I exit, of course, I execute the 'EOI', but I don't make the 'STI'
instruction. Sometimes, the handler is called but the interrupt flag is not
restore.

  Is correctI if I put a STI instruction before the EOI instruction or the
go32 wrapper does this for me?
  If I put a STI, could I have problems if another interrupt is called?

  I'm looking forward to hearing from you.  Thanks world.

                            Javier Calleja