From: John Feeney <jfeeney@redhat.com>
Date: Tue, 15 Jan 2008 17:26:31 -0500
Subject: [ide] handle DRAC4 hotplug
Message-id: 478D3317.40803@redhat.com
O-Subject: Re: [RHEL-5.2 PATCH] IDE (siimage) panics when DRAC4 reset
Bugzilla: 212391

A repost of a previously posted patch by Alan Cox.
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=212391
bz212391 IDE (siimage) driver causes panic with DRAC4 reset

This patch was posted to rhkernel-list and accepted for the
RHEL-5.1 timeframe but if failed verification when it was
determined that a conflict with the SATA Super Jumbo patch,
developed at the same time, caused a piece of this patch to be
no longer compiled (the new module's Kconfig had a dependency
on SCSI_SATA which was removed by the SATA Super
Jumbo patch). The verification failure was found (too) late in the
RHEL-5.1 cycle and so the patch was removed from RHEL-5.1.

The RHEL-5.1 patch required some changes dictated by the SATA
Super Jumbo patch (remove deadline arg, change host_set variable
name to host, add ata_irq_on and ata_irq_ack to structure, remove
ata_port_stop and ata_host_stop from structure, and change host_flags
variable name to flags).

The patch below was successfully tested by Dell.

Note that this adds a new module, thus
CONFIG_SCSI_PATA_SIL680_DRAC will need to be added,
Don.

Again, for more details, here is some of what Alan wrote the first time...

The Dell DRAC4 effectively does hotplug on the virtual CD/Floppy devices
that it provides. This can cause a kernel crash with the old IDE layer.
Dell
tested the new libata layer and found it handles it fine.

As we cannot switch to libata midstream for other devices this patch
adds a suitable version of pata_sil680 combined with checks in both siimage
and pata_sil680 to load the right driver for the right SIL680 card. This
is ugly because there is no vendor subid to key off.

Other oddity is the PCI table for the pata_sil680 which is exported to the
module layer, this doesn't match the one used for the driver but ensures
that
the right driver is loaded when the DRAC4 is present.

As always, acks would be appreciated.

diff --git a/drivers/ata/pata_sil680.c b/drivers/ata/pata_sil680.c
index 503245a..0229947 100644
--- a/drivers/ata/pata_sil680.c
+++ b/drivers/ata/pata_sil680.c
@@ -338,6 +338,31 @@ static int __devinit sil680_init_one(struct pci_dev *pdev,
 	struct ata_host *host;
 	void __iomem *mmio_base;
 	int rc, try_mmio;
+	struct pci_dev *drac;
+
+	/* DRAC only filter */
+
+	drac = pci_get_device(PCI_VENDOR_ID_DELL, PCI_DEVICE_ID_DELL_RAC4,
+			      NULL);
+
+	if (drac == NULL) {
+	    /* There are two common devices on DRACs. See if we can *
+	     * find the second one if couldn't find the first.      */
+	    printk(KERN_INFO "sil680: Trying SMIC device.\n");
+	    drac = pci_get_device(PCI_VENDOR_ID_DELL, 0x0014, NULL);
+	}
+
+	if (drac == NULL)
+	    return -ENODEV;
+
+	if (drac->bus != pdev->bus)     /* Not the right SIL680 */
+	{
+	    pci_dev_put(drac);
+	    return -ENODEV;
+	}
+	pci_dev_put(drac);
+
+	/* Back to original code */
 
 	if (!printed_version++)
 		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");
diff --git a/drivers/ide/pci/siimage.c b/drivers/ide/pci/siimage.c
index 20b3929..9517586 100644
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -1078,6 +1078,26 @@ static ide_pci_device_t siimage_chipsets[] __devinitdata = {
  
 static int __devinit siimage_init_one(struct pci_dev *dev, const struct pci_device_id *id)
 {
+	struct pci_dev *drac = pci_get_device(PCI_VENDOR_ID_DELL,
+					      PCI_DEVICE_ID_DELL_RAC4, NULL);
+
+	if (drac == NULL) {
+	    /* There are two common devices on DRACs. See if we can *
+	     * find the second one if couldn't find the first.      */
+	    drac = pci_get_device(PCI_VENDOR_ID_DELL,
+				  0x0014, NULL);
+	}
+
+	if (drac) {
+	    /* Watch out, watch out, there's a DRAC about ! */
+	    if (drac->bus == dev->bus) {
+	        pci_dev_put(drac);
+	        printk(KERN_INFO "siimage: Ignoring DRAC controller.\n");
+		return -ENODEV;
+	    }
+	    pci_dev_put(drac);
+	}
+
 	return ide_setup_pci_device(dev, &siimage_chipsets[id->driver_data]);
 }