Patch(2.4.5): Fix PCMCIA ATA/IDE freeze (w/ PCI add-in cards)

[Gunther.Mayer@t-online.de (Gunther Mayer)]

Hi,

this patch fixes the hard hang (no SYSRQ) on inserting
any PCMCIA ATA/IDE card (e.g. CompactFlash, Clik40 etc)
to a PCI-Cardbus bridge add-in card.

Thanks David for his valuable explanation about what happens:
ide-probe registers it's irq handler too late! After it
triggers the interrupt during the probe the (shared) irq
loops forever, effectively wedging the machine completely.

Regards, Gunther



--- linux245.orig/drivers/ide/ide-cs.c  Fri Feb  9 20:40:02 2001
+++ linux/drivers/ide/ide-cs.c  Tue Jun 26 21:22:19 2001
@@ -324,6 +324,9 @@
     if (link->io.NumPorts2)
        release_region(link->io.BasePort2, link->io.NumPorts2);
 
+    outb(0x02, ctl_base); // Set nIEN = disable device interrupts
+                         // else it hangs on PCI-Cardbus add-in cards, wedging irq
+
     /* retry registration in case device is still spinning up */
     for (i = 0; i < 10; i++) {
        hd = ide_register(io_base, ctl_base, link->irq.AssignedIRQ);
--- linux245.orig/drivers/ide/ide-probe.c       Sun Mar 18 18:25:02 2001
+++ linux/drivers/ide/ide-probe.c       Tue Jun 26 21:25:07 2001
@@ -685,6 +685,8 @@
 #else /* !CONFIG_IDEPCI_SHARE_IRQ */
                int sa = (hwif->chipset == ide_pci) ? SA_INTERRUPT|SA_SHIRQ : SA_INTERRUPT;
 #endif /* CONFIG_IDEPCI_SHARE_IRQ */
+
+               outb(0x00, hwif->io_ports[IDE_CONTROL_OFFSET]); // clear nIEN == enable irqs
                if (ide_request_irq(hwif->irq, &ide_intr, sa, hwif->name, hwgroup)) {
                        if (!match)
                                kfree(hwgroup);