From: Scott Moser <smoser@redhat.com>
Subject: Re: [RHEL5.1 PATCH] bz184774 [PPC] IDE hotplug support for Promise  pata_pdc2027x
Date: Wed, 20 Jun 2007 15:59:47 -0400 (EDT)
Bugzilla: 184774
Message-Id: <Pine.LNX.4.64.0706201554390.18157@squad5-lp1.lab.boston.redhat.com>
Changelog: [pata] IDE hotplug support for Promise pata_pdc2027x


The patch below will make hotplug via DLPAR work. This has been tested by
Albert Lee of IBM (who originally posted the fix for this bug).

We simply  need to:
   1. apply the patch
   2. set CONFIG_PATA_PDC2027X=m.

Unfortunately, all is not perfect.  If the device is present, unloading
the module (rmmod pata_pdc2027x) and then reloading will result in the
following error in dmesg (and a  non-working device):
  PCI: Unable to reserve mem region #6:4000@401f8000000 for device 0000:cc:01.0
  pata_pdc2027x: probe of 0000:cc:01.0 failed with error -16

Even if it were not fixed, IBM would be happy to live with the 'rmmod'
issue with the patch applied.

The patch basically does 3 things:
  1. changes the ide driver to not claim the device in IBM power hardware
  2. removes IDs for other devices from the sata driver so that only this
device ID is present in both the ide and sata drivers.
  3. modifies the sata driver to refuse to initialize any device on
systems other than the intended IBM supported system.

---
 drivers/ata/pata_pdc2027x.c    |   14 ++++++++------
 drivers/ide/pci/pdc202xx_new.c |   12 ++++++++++++
 2 files changed, 20 insertions(+), 6 deletions(-)

Index: linux-2.6.18.ppc64/drivers/ide/pci/pdc202xx_new.c
===================================================================
--- linux-2.6.18.ppc64.orig/drivers/ide/pci/pdc202xx_new.c
+++ linux-2.6.18.ppc64/drivers/ide/pci/pdc202xx_new.c
@@ -355,6 +355,18 @@ static void __devinit init_hwif_pdc202ne
 
 static int __devinit init_setup_pdcnew(struct pci_dev *dev, ide_pci_device_t *d)
 {
+#ifdef __powerpc64__
+	/* Skip using the IDE device driver on IBM p5 machines
+	 * to load the libata hotplug driver instead later
+	 */
+	if (dev->bus->self &&
+	    dev->bus->self->vendor == PCI_VENDOR_ID_IBM &&
+	    dev->bus->self->device == 0x0188) {
+		printk(KERN_INFO "ide: Skipping Promise PDC20275 "
+		       "on IBM p5 machines.\n");
+		return -ENODEV;
+	}
+#endif
 	return ide_setup_pci_device(dev, d);
 }
 
--- a/drivers/ata/pata_pdc2027x.c	2007-06-20 15:42:08.000000000 -0400
+++ b/drivers/ata/pata_pdc2027x.c	2007-06-20 15:39:09.000000000 -0400
@@ -110,13 +110,7 @@
 };
 
 static const struct pci_device_id pdc2027x_pci_tbl[] = {
-	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20268), PDC_UDMA_100 },
-	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20269), PDC_UDMA_133 },
-	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20270), PDC_UDMA_100 },
-	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20271), PDC_UDMA_133 },
 	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20275), PDC_UDMA_133 },
-	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20276), PDC_UDMA_133 },
-	{ PCI_VDEVICE(PROMISE, PCI_DEVICE_ID_PROMISE_20277), PDC_UDMA_133 },
 
 	{ }	/* terminate list */
 };
@@ -794,6 +788,14 @@
 	if (!printed_version++)
 		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");
 
+	/* load only on IBM p5 machines */
+	if (!(pdev->bus->self &&
+	    pdev->bus->self->vendor == PCI_VENDOR_ID_IBM &&
+	    pdev->bus->self->device == 0x0188)) {
+		printk(KERN_INFO "device ignored. only supported on IBM p5 machines");
+		return -ENODEV;
+	}
+
 	/* alloc host */
 	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
 	if (!host)