[PATCH] pata_cs5536: ATA driver for Geode companion chip

[PATCH] pata_cs5536: ATA driver for Geode companion chip

[Martin K. Petersen]

This is a driver for the ATA controller on the Geode CS5536 companion
chip.  The PCI device ID for this device was previously claimed by
pata_amd.c but the PIO timings were not correct.  This driver also
works around a bug in some BIOSes that handle unaligned access to the
PCI config registers poorly.  Finally, the driver allows fallback to
using MSR registers for configuration on BIOSes that are truly
broken.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

---

diff -r 79f0ea1e0e70 drivers/ata/Kconfig
--- a/drivers/ata/Kconfig	Tue Oct 09 21:00:40 2007 +0000
+++ b/drivers/ata/Kconfig	Thu Oct 11 03:26:40 2007 -0400
@@ -254,6 +254,15 @@ config PATA_CS5535
 
 	  If unsure, say N.
 
+config PATA_CS5536
+	tristate "CS5536 PATA support (Experimental)"
+	depends on PCI && X86 && !X86_64 && EXPERIMENTAL
+	help
+	  This option enables support for the AMD CS5536
+	  companion chip used with the Geode LX processor family.
+
+	  If unsure, say N.
+
 config PATA_CYPRESS
 	tristate "Cypress CY82C693 PATA support (Very Experimental)"
 	depends on PCI && EXPERIMENTAL
diff -r 79f0ea1e0e70 drivers/ata/Makefile
--- a/drivers/ata/Makefile	Tue Oct 09 21:00:40 2007 +0000
+++ b/drivers/ata/Makefile	Thu Oct 11 03:26:40 2007 -0400
@@ -27,6 +27,7 @@ obj-$(CONFIG_PATA_CS5520)	+= pata_cs5520
 obj-$(CONFIG_PATA_CS5520)	+= pata_cs5520.o
 obj-$(CONFIG_PATA_CS5530)	+= pata_cs5530.o
 obj-$(CONFIG_PATA_CS5535)	+= pata_cs5535.o
+obj-$(CONFIG_PATA_CS5536)	+= pata_cs5536.o
 obj-$(CONFIG_PATA_CYPRESS)	+= pata_cypress.o
 obj-$(CONFIG_PATA_EFAR)		+= pata_efar.o
 obj-$(CONFIG_PATA_HPT366)	+= pata_hpt366.o
diff -r 79f0ea1e0e70 drivers/ata/pata_amd.c
--- a/drivers/ata/pata_amd.c	Tue Oct 09 21:00:40 2007 +0000
+++ b/drivers/ata/pata_amd.c	Thu Oct 11 03:26:40 2007 -0400
@@ -693,7 +693,10 @@ static const struct pci_device_id amd[] 
 	{ PCI_VDEVICE(NVIDIA,	PCI_DEVICE_ID_NVIDIA_NFORCE_MCP67_IDE),	8 },
 	{ PCI_VDEVICE(NVIDIA,	PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_IDE),	8 },
 	{ PCI_VDEVICE(NVIDIA,	PCI_DEVICE_ID_NVIDIA_NFORCE_MCP77_IDE),	8 },
+/* Temporary */
+#if !defined(CONFIG_PATA_CS5536) && !defined(CONFIG_PATA_CS5536_MODULE)
 	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_IDE),		9 },
+#endif
 
 	{ },
 };
diff -r 79f0ea1e0e70 drivers/ata/pata_cs5536.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/drivers/ata/pata_cs5536.c	Thu Oct 11 03:26:40 2007 -0400
@@ -0,0 +1,346 @@
+/*
+ * pata_cs5536.c	- CS5536 PATA for new ATA layer
+ *			  (C) 2007 Martin K. Petersen <mkp@mkp.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307	 USA
+ *
+ * Documentation:
+ *	Available from AMD web site.
+ *
+ * The IDE timing registers for the CS5536 live in the Geode Machine
+ * Specific Register file and not PCI config space.  Most BIOSes
+ * virtualize the PCI registers so the chip looks like a standard IDE
+ * controller.	Unfortunately not all implementations get this right.
+ * In particular some have problems with unaligned accesses to the
+ * virtualized PCI registers.  This driver always does full dword
+ * writes to work around the issue.  Also, in case of a bad BIOS this
+ * driver can be loaded with the "msr=1" parameter which forces using
+ * the Machine Specific Registers to configure the device.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/libata.h>
+#include <scsi/scsi_host.h>
+#include <asm/msr.h>
+
+#define DRV_NAME	"pata_cs5536"
+#define DRV_VERSION	"0.0.5"
+
+enum {
+	CFG			= 0,
+	DTC			= 1,
+	CAST			= 2,
+	ETC			= 3,
+
+	MSR_IDE_BASE		= 0x51300000,
+	MSR_IDE_CFG		= (MSR_IDE_BASE + 0x10),
+	MSR_IDE_DTC		= (MSR_IDE_BASE + 0x12),
+	MSR_IDE_CAST		= (MSR_IDE_BASE + 0x13),
+	MSR_IDE_ETC		= (MSR_IDE_BASE + 0x14),
+
+	PCI_IDE_CFG		= 0x40,
+	PCI_IDE_DTC		= 0x48,
+	PCI_IDE_CAST		= 0x4c,
+	PCI_IDE_ETC		= 0x50,
+
+	IDE_CFG_CHANEN		= 0x2,
+	IDE_CFG_CABLE		= 0x10000,
+
+	IDE_D0_SHIFT		= 24,
+	IDE_D1_SHIFT		= 16,
+	IDE_DRV_MASK		= 0xff,
+
+	IDE_CAST_D0_SHIFT	= 6,
+	IDE_CAST_D1_SHIFT	= 4,
+	IDE_CAST_DRV_MASK	= 0x3,
+	IDE_CAST_CMD_MASK	= 0xff,
+	IDE_CAST_CMD_SHIFT	= 24,
+
+	IDE_ETC_NODMA		= 0x03,
+};
+
+static int use_msr;
+
+static const u32 msr_reg[4] = {
+	MSR_IDE_CFG, MSR_IDE_DTC, MSR_IDE_CAST, MSR_IDE_ETC,
+};
+
+static const u8 pci_reg[4] = {
+	PCI_IDE_CFG, PCI_IDE_DTC, PCI_IDE_CAST, PCI_IDE_ETC,
+};
+
+static inline int cs5536_read(struct pci_dev *pdev, int reg, int *val)
+{
+	if (unlikely(use_msr)) {
+		u32 dummy;
+
+		rdmsr(msr_reg[reg], *val, dummy);
+		return 0;
+	}
+
+	return pci_read_config_dword(pdev, pci_reg[reg], val);
+}
+
+static inline int cs5536_write(struct pci_dev *pdev, int reg, int val)
+{
+	if (unlikely(use_msr)) {
+		wrmsr(msr_reg[reg], val, 0);
+		return 0;
+	}
+
+	return pci_write_config_dword(pdev, pci_reg[reg], val);
+}
+
+/**
+ *	cs5536_cable_detect	-	detect cable type
+ *	@ap: Port to detect on
+ *	@deadline: deadline jiffies for the operation
+ *
+ *	Perform cable detection for ATA66 capable cable. Return a libata
+ *	cable type.
+ */
+
+static int cs5536_cable_detect(struct ata_port *ap)
+{
+	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
+	u32 cfg;
+
+	cs5536_read(pdev, CFG, &cfg);
+
+	if (cfg & (IDE_CFG_CABLE << ap->port_no))
+		return ATA_CBL_PATA80;
+	else
+		return ATA_CBL_PATA40;
+}
+
+/**
+ *	cs5536_set_piomode		-	PIO setup
+ *	@ap: ATA interface
+ *	@adev: device on the interface
+ */
+
+static void cs5536_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	static const u8 drv_timings[5] = {
+		0x98, 0x55, 0x32, 0x21, 0x20,
+	};
+
+	static const u8 addr_timings[5] = {
+		0x2, 0x1, 0x0, 0x0, 0x0,
+	};
+
+	static const u8 cmd_timings[5] = {
+		0x99, 0x92, 0x90, 0x22, 0x20,
+	};
+
+	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
+	struct ata_device *pair = ata_dev_pair(adev);
+	int mode = adev->pio_mode - XFER_PIO_0;
+	int cmdmode = mode;
+	int dshift = ap->port_no ? IDE_D1_SHIFT : IDE_D0_SHIFT;
+	int cshift = ap->port_no ? IDE_CAST_D1_SHIFT : IDE_CAST_D0_SHIFT;
+	u32 dtc, cast, etc;
+
+	if (pair)
+		cmdmode = min(mode, pair->pio_mode - XFER_PIO_0);
+
+	cs5536_read(pdev, DTC, &dtc);
+	cs5536_read(pdev, CAST, &cast);
+	cs5536_read(pdev, ETC, &etc);
+
+	dtc &= ~(IDE_DRV_MASK << dshift);
+	dtc |= drv_timings[mode] << dshift;
+
+	cast &= ~(IDE_CAST_DRV_MASK << cshift);
+	cast |= addr_timings[mode] << cshift;
+
+	cast &= ~(IDE_CAST_CMD_MASK << IDE_CAST_CMD_SHIFT);
+	cast |= cmd_timings[cmdmode] << IDE_CAST_CMD_SHIFT;
+
+	etc &= ~(IDE_DRV_MASK << dshift);
+	etc |= IDE_ETC_NODMA << dshift;
+
+	cs5536_write(pdev, DTC, dtc);
+	cs5536_write(pdev, CAST, cast);
+	cs5536_write(pdev, ETC, etc);
+}
+
+/**
+ *	cs5536_set_dmamode		-	DMA timing setup
+ *	@ap: ATA interface
+ *	@adev: Device being configured
+ *
+ */
+
+static void cs5536_set_dmamode(struct ata_port *ap, struct ata_device *adev)
+{
+	static const u8 udma_timings[6] = {
+		0xc2, 0xc1, 0xc0, 0xc4, 0xc5, 0xc6,
+	};
+
+	static const u8 mwdma_timings[3] = {
+		0x67, 0x21, 0x20,
+	};
+
+	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
+	u32 dtc, etc;
+	int mode = adev->dma_mode;
+	int dshift = ap->port_no ? IDE_D1_SHIFT : IDE_D0_SHIFT;
+
+	if (mode >= XFER_UDMA_0) {
+		cs5536_read(pdev, ETC, &etc);
+
+		etc &= ~(IDE_DRV_MASK << dshift);
+		etc |= udma_timings[mode - XFER_UDMA_0] << dshift;
+
+		cs5536_write(pdev, ETC, etc);
+	} else { /* MWDMA */
+		cs5536_read(pdev, DTC, &dtc);
+
+		dtc &= ~(IDE_DRV_MASK << dshift);
+		dtc |= mwdma_timings[mode] << dshift;
+
+		cs5536_write(pdev, DTC, dtc);
+	}
+}
+
+static struct scsi_host_template cs5536_sht = {
+	.module			= THIS_MODULE,
+	.name			= DRV_NAME,
+	.ioctl			= ata_scsi_ioctl,
+	.queuecommand		= ata_scsi_queuecmd,
+	.can_queue		= ATA_DEF_QUEUE,
+	.this_id		= ATA_SHT_THIS_ID,
+	.sg_tablesize		= LIBATA_MAX_PRD,
+	.cmd_per_lun		= ATA_SHT_CMD_PER_LUN,
+	.emulated		= ATA_SHT_EMULATED,
+	.use_clustering		= ATA_SHT_USE_CLUSTERING,
+	.proc_name		= DRV_NAME,
+	.dma_boundary		= ATA_DMA_BOUNDARY,
+	.slave_configure	= ata_scsi_slave_config,
+	.slave_destroy		= ata_scsi_slave_destroy,
+	.bios_param		= ata_std_bios_param,
+};
+
+static struct ata_port_operations cs5536_port_ops = {
+	.port_disable		= ata_port_disable,
+	.set_piomode		= cs5536_set_piomode,
+	.set_dmamode		= cs5536_set_dmamode,
+	.mode_filter		= ata_pci_default_filter,
+
+	.tf_load		= ata_tf_load,
+	.tf_read		= ata_tf_read,
+	.check_status		= ata_check_status,
+	.exec_command		= ata_exec_command,
+	.dev_select		= ata_std_dev_select,
+
+	.freeze			= ata_bmdma_freeze,
+	.thaw			= ata_bmdma_thaw,
+	.error_handler		= ata_bmdma_error_handler,
+	.post_internal_cmd	= ata_bmdma_post_internal_cmd,
+	.cable_detect		= cs5536_cable_detect,
+
+	.bmdma_setup		= ata_bmdma_setup,
+	.bmdma_start		= ata_bmdma_start,
+	.bmdma_stop		= ata_bmdma_stop,
+	.bmdma_status		= ata_bmdma_status,
+
+	.qc_prep		= ata_qc_prep,
+	.qc_issue		= ata_qc_issue_prot,
+
+	.data_xfer		= ata_data_xfer,
+
+	.irq_handler		= ata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
+	.irq_on			= ata_irq_on,
+	.irq_ack		= ata_irq_ack,
+
+	.port_start		= ata_port_start,
+};
+
+/**
+ *	cs5536_init_one
+ *	@dev: PCI device
+ *	@id: Entry in match table
+ *
+ */
+
+static int cs5536_init_one(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	static const struct ata_port_info info = {
+		.sht = &cs5536_sht,
+		.flags = ATA_FLAG_SLAVE_POSS,
+		.pio_mask = 0x1f,
+		.mwdma_mask = 0x07,
+		.udma_mask = ATA_UDMA5,
+		.port_ops = &cs5536_port_ops,
+	};
+
+	const struct ata_port_info *ppi[] = { &info, &ata_dummy_port_info };
+	u32 cfg;
+
+	if (use_msr)
+		printk(KERN_ERR DRV_NAME ": Using MSR regs instead of PCI\n");
+
+	cs5536_read(dev, CFG, &cfg);
+
+	if ((cfg & IDE_CFG_CHANEN) == 0) {
+		printk(KERN_ERR DRV_NAME ": disabled by BIOS\n");
+		return -ENODEV;
+	}
+
+	return ata_pci_init_one(dev, ppi);
+}
+
+static const struct pci_device_id cs5536[] = {
+	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_IDE), },
+	{ },
+};
+
+static struct pci_driver cs5536_pci_driver = {
+	.name		= DRV_NAME,
+	.id_table	= cs5536,
+	.probe		= cs5536_init_one,
+	.remove		= ata_pci_remove_one,
+#ifdef CONFIG_PM
+	.suspend	= ata_pci_device_suspend,
+	.resume		= ata_pci_device_resume,
+#endif
+};
+
+static int __init cs5536_init(void)
+{
+	return pci_register_driver(&cs5536_pci_driver);
+}
+
+static void __exit cs5536_exit(void)
+{
+	pci_unregister_driver(&cs5536_pci_driver);
+}
+
+MODULE_AUTHOR("Martin K. Petersen");
+MODULE_DESCRIPTION("low-level driver for the CS5536 IDE controller");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(pci, cs5536);
+MODULE_VERSION(DRV_VERSION);
+module_param_named(msr, use_msr, int, 0644);
+MODULE_PARM_DESC(msr, "Force using MSR to configure IDE function (Default: 0)");
+
+module_init(cs5536_init);
+module_exit(cs5536_exit);

Re: [PATCH] pata_cs5536: ATA driver for Geode companion chip

[Alan Cox]

On Thu, 11 Oct 2007 03:38:19 -0400
"Martin K. Petersen" <martin.petersen@oracle.com> wrote:

> 
> This is a driver for the ATA controller on the Geode CS5536 companion
> chip.  The PCI device ID for this device was previously claimed by
> pata_amd.c but the PIO timings were not correct.  This driver also
> works around a bug in some BIOSes that handle unaligned access to the
> PCI config registers poorly.  Finally, the driver allows fallback to
> using MSR registers for configuration on BIOSes that are truly
> broken.
> 
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Acked-by: Alan Cox <alan@redhat.com>

Re: [PATCH] pata_cs5536: ATA driver for Geode companion chip

[Andrew Paprocki]

On 10/11/07, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> On Thu, 11 Oct 2007 03:38:19 -0400
> "Martin K. Petersen" <martin.petersen@oracle.com> wrote:
>
> >
> > This is a driver for the ATA controller on the Geode CS5536 companion
> > chip.  The PCI device ID for this device was previously claimed by
> > pata_amd.c but the PIO timings were not correct.  This driver also
> > works around a bug in some BIOSes that handle unaligned access to the
> > PCI config registers poorly.  Finally, the driver allows fallback to
> > using MSR registers for configuration on BIOSes that are truly
> > broken.
> >
> > Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
>
> Acked-by: Alan Cox <alan@redhat.com>

I've been using the driver (boot drive on the port) since Martin's
post and haven't experienced any problems.

Tested-by: Andrew Paprocki <andrew@ishiboo.com>

Re: [PATCH] pata_cs5536: ATA driver for Geode companion chip

[Andrew Paprocki]

Just noticed something.. I'm not sure if this is due to a libata-dev
change or me switching to pata_cs5536, but my 128MB DOM on the PATA
port is hitting the ata_dma_blacklisted() case and it was not
previously. This did not happen under 2.6.22.6 using pata_amd. The
system is noticeably slower when forced to use PIO4 (as you would
expect).

Is this expected in the newer code, or is it a bug?

Previous 2.6.22.6 kernel using pata_amd:

pata_amd 0000:00:0f.2: version 0.3.8
scsi4 : pata_amd
scsi5 : pata_amd
ata5: PATA max UDMA/100 cmd 0x000101f0 ctl 0x000103f6 bmdma 0x0001ff00 irq 14
ata6: PATA max UDMA/100 cmd 0x00010170 ctl 0x00010376 bmdma 0x0001ff08 irq 15
ata5.00: ATA-0: , 060729DA, max MWDMA2
ata5.00: 256000 sectors, multi 1: LBA
ata5.00: configured for MWDMA2
ata6: port disabled. ignoring.

Up-to-date libata-dev using pata_cs5536:

scsi4 : pata_cs5536
scsi5 : pata_cs5536
ata5: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0xff00 irq 14
ata6: DUMMY
ata5: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0xff00 irq 14
ata5.00: ATA-0: , 060729DA, max MWDMA2
ata5.00: 256000 sectors, multi 1: LBA
ata5.00: device is on DMA blacklist, disabling DMA
ata5.00: configured for PIO4
ata5.00: device is on DMA blacklist, disabling DMA
ata5.00: configured for PIO4
ata5: EH complete

Thanks,
-Andrew

On 10/14/07, Andrew Paprocki <andrew@ishiboo.com> wrote:
> On 10/11/07, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> > On Thu, 11 Oct 2007 03:38:19 -0400
> > "Martin K. Petersen" <martin.petersen@oracle.com> wrote:
> >
> > >
> > > This is a driver for the ATA controller on the Geode CS5536 companion
> > > chip.  The PCI device ID for this device was previously claimed by
> > > pata_amd.c but the PIO timings were not correct.  This driver also
> > > works around a bug in some BIOSes that handle unaligned access to the
> > > PCI config registers poorly.  Finally, the driver allows fallback to
> > > using MSR registers for configuration on BIOSes that are truly
> > > broken.
> > >
> > > Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> >
> > Acked-by: Alan Cox <alan@redhat.com>
>
> I've been using the driver (boot drive on the port) since Martin's
> post and haven't experienced any problems.
>
> Tested-by: Andrew Paprocki <andrew@ishiboo.com>

Re: [PATCH] pata_cs5536: ATA driver for Geode companion chip

[Alan Cox]

On Sun, 14 Oct 2007 15:42:19 -0400
"Andrew Paprocki" <andrew.m.paprocki@gmail.com> wrote:

> Just noticed something.. I'm not sure if this is due to a libata-dev
> change or me switching to pata_cs5536, but my 128MB DOM on the PATA
> port is hitting the ata_dma_blacklisted() case and it was not
> previously. This did not happen under 2.6.22.6 using pata_amd. The
> system is noticeably slower when forced to use PIO4 (as you would
> expect).
> 
> Is this expected in the newer code, or is it a bug?

Sounds like someone added it wrongly to the blacklist. Remove the
blacklist entry, test again and if DMA is working we need to get that
fixed ASAP in .2 and 2.6.24.

Alan

Re: [PATCH] pata_cs5536: ATA driver for Geode companion chip

[Andrew Paprocki]

Long story short -- this has nothing to do with pata_cs5536.

It isn't in that list! I just patched my kernel to print the reason
why it is being blacklisted and this turned up:

ata5.00: ATA-0: , 060729DA, max MWDMA2
ata5.00: 256000 sectors, multi 1: LBA
ata5.00: device is on DMA blacklist, disabling DMA
ata5.00: device matched DMA blacklist, model: WDC AC11000H
ata5.00: configured for PIO4

The strn_pattern_cmp function does not handle blank model names. I
would like to give this Taiwanese manufacturer a bug for not bothering
to put a model name on their device, but I don't think they'll care
too much.. :)

I just submitted a patch to fix strn_pattern_cmp to handle the
strlen(name)==0 case appropriately (ie only match it against "*" or
"").

With that change, it is properly detected as MWDMA2 again:

ata5.00: ATA-0: , 060729DA, max MWDMA2
ata5.00: 256000 sectors, multi 1: LBA
ata5.00: configured for MWDMA2
ata5.00: configured for MWDMA2

Thanks,
-Andrew

On 10/14/07, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> On Sun, 14 Oct 2007 15:42:19 -0400
> "Andrew Paprocki" <andrew.m.paprocki@gmail.com> wrote:
>
> > Just noticed something.. I'm not sure if this is due to a libata-dev
> > change or me switching to pata_cs5536, but my 128MB DOM on the PATA
> > port is hitting the ata_dma_blacklisted() case and it was not
> > previously. This did not happen under 2.6.22.6 using pata_amd. The
> > system is noticeably slower when forced to use PIO4 (as you would
> > expect).
> >
> > Is this expected in the newer code, or is it a bug?
>
> Sounds like someone added it wrongly to the blacklist. Remove the
> blacklist entry, test again and if DMA is working we need to get that
> fixed ASAP in .2 and 2.6.24.
>
> Alan

Re: [PATCH] pata_cs5536: ATA driver for Geode companion chip

[Jeff Garzik]

Martin K. Petersen wrote:
> This is a driver for the ATA controller on the Geode CS5536 companion
> chip.  The PCI device ID for this device was previously claimed by
> pata_amd.c but the PIO timings were not correct.  This driver also
> works around a bug in some BIOSes that handle unaligned access to the
> PCI config registers poorly.  Finally, the driver allows fallback to
> using MSR registers for configuration on BIOSes that are truly
> broken.
> 
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> 
> ---
> 
> diff -r 79f0ea1e0e70 drivers/ata/Kconfig
> --- a/drivers/ata/Kconfig	Tue Oct 09 21:00:40 2007 +0000
> +++ b/drivers/ata/Kconfig	Thu Oct 11 03:26:40 2007 -0400
> @@ -254,6 +254,15 @@ config PATA_CS5535
>  
>  	  If unsure, say N.
>  
> +config PATA_CS5536
> +	tristate "CS5536 PATA support (Experimental)"
> +	depends on PCI && X86 && !X86_64 && EXPERIMENTAL
> +	help
> +	  This option enables support for the AMD CS5536
> +	  companion chip used with the Geode LX processor family.
> +
> +	  If unsure, say N.
> +
>  config PATA_CYPRESS
>  	tristate "Cypress CY82C693 PATA support (Very Experimental)"
>  	depends on PCI && EXPERIMENTAL
> diff -r 79f0ea1e0e70 drivers/ata/Makefile
> --- a/drivers/ata/Makefile	Tue Oct 09 21:00:40 2007 +0000
> +++ b/drivers/ata/Makefile	Thu Oct 11 03:26:40 2007 -0400
> @@ -27,6 +27,7 @@ obj-$(CONFIG_PATA_CS5520)	+= pata_cs5520
>  obj-$(CONFIG_PATA_CS5520)	+= pata_cs5520.o
>  obj-$(CONFIG_PATA_CS5530)	+= pata_cs5530.o
>  obj-$(CONFIG_PATA_CS5535)	+= pata_cs5535.o
> +obj-$(CONFIG_PATA_CS5536)	+= pata_cs5536.o
>  obj-$(CONFIG_PATA_CYPRESS)	+= pata_cypress.o
>  obj-$(CONFIG_PATA_EFAR)		+= pata_efar.o
>  obj-$(CONFIG_PATA_HPT366)	+= pata_hpt366.o
> diff -r 79f0ea1e0e70 drivers/ata/pata_amd.c
> --- a/drivers/ata/pata_amd.c	Tue Oct 09 21:00:40 2007 +0000
> +++ b/drivers/ata/pata_amd.c	Thu Oct 11 03:26:40 2007 -0400
> @@ -693,7 +693,10 @@ static const struct pci_device_id amd[] 
>  	{ PCI_VDEVICE(NVIDIA,	PCI_DEVICE_ID_NVIDIA_NFORCE_MCP67_IDE),	8 },
>  	{ PCI_VDEVICE(NVIDIA,	PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_IDE),	8 },
>  	{ PCI_VDEVICE(NVIDIA,	PCI_DEVICE_ID_NVIDIA_NFORCE_MCP77_IDE),	8 },
> +/* Temporary */
> +#if !defined(CONFIG_PATA_CS5536) && !defined(CONFIG_PATA_CS5536_MODULE)
>  	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_IDE),		9 },
> +#endif
>  
>  	{ },
>  };

applied, after removing the pata_amd patch

I don't typically apply things marked temporary :) but moreover, this is 
a bit unusual to do in a driver.  Any opinions on simply removing the 
PCI ID?  what's the installed base like today?  do we need to keep the 
PCI ID in both drivers?