From mboxrd@z Thu Jan 1 00:00:00 1970 In-Reply-To: <199908310148.LAA14647@tango.anu.edu.au> Date: Tue, 31 Aug 1999 15:08:26 +0200 To: Paul.Mackerras@cs.anu.edu.au, linuxppc-dev@lists.linuxppc.org From: Benjamin Herrenschmidt Subject: Improving gatwick interrupts Message-Id: <19990831150826.024152@mailhost.mipsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Hi ! The current implementation of the interrupt handler for gatwick (the second mac-io found on some PowerBooks) is not perfect. Currently, it's a special handler for the cascaded interrupt which will decode the GW interrupt and call back recursively the ppc_irq_dispatch_handler. That means that while a given GW interrupt is beeing handled, all other GW interrupts are suspended (masked). In theory, once we have ask&mask'ed the real interrupt in GW controller, we could re-enable the GW cascade interrupt itself to let other interrupts come in from the second controller. The problem is that it requires an awful hack to the current architecture, like passing a special parameter to ppc_irq_dispatch_handler with the interrupt to re-enable after the ack&mask operation. Do you think there is interest in doing that ? Currently, the only possible users of GW interrupts are the internal modem of the wallstreet, the left media bay IDE devices or the left media bay floppies. -- Perso. e-mail: Work e-mail: BenH. Web : [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. Please check http://lists.linuxppc.org/ ]] [[ and http://www.linuxppc.org/ for useful information before posting. ]]