[lkml]   [2005]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH] PCI: Add pci shutdown ability
    On Tue, 26 Apr 2005, Grant Grundler wrote:

    > > I looked into the possibility of having the PCI core disable interrupt
    > > generation and DMA on each new device as it is discovered. Unfortunately
    > > there is no dependable, universal way to do this for IRQs.
    > Sure there is. Every IRQ line goes to an IRQ controller.
    > Arch specific code deals with programming the controller and can
    > mask all interrupts (or not). Historically, they've been left unmasked
    > for ISA IRQ discovery and debugging misrouted IRQ lines.

    This doesn't help. Consider what happens when two devices share an IRQ
    line. Suppose device B is generating interrupt requests when the driver
    for device A is probed. The driver registers its handler, which causes
    the IRQ line to be unmasked. Then a multitude of IRQs arrive from B, none
    of which can be handled by A's driver. So the kernel shuts the IRQ line
    down permanently...

    Alan Stern

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-04-26 18:13    [W:0.032 / U:4.020 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site