Commit abf8f2b8 authored by Christian Gmeiner's avatar Christian Gmeiner Committed by Jeff Garzik
Browse files

pata_cs5536: add quirk for broken udma 



I am working on a device which uses the cs5536 pata driver. There
are some broken hardware revisions out in the field, which can be
detected via DMI. On older versions with an embedded BIOS I
used libata.dma=0 to disable dma completely.
Now we are switching to a coreboot/seabios based BIOS where we
have DMI support and so I think its a good idea to get rid of
all those hacky kernel parameters as the same image
is used other devices where libata.dma=0 is not a good idea.

Signed-off-by: default avatarChristian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent d9904344

drivers/ata/pata_cs5536.c

+31 −1
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include <linux/delay.h>

#include <linux/libata.h>

#include <scsi/scsi_host.h>

#include <linux/dmi.h>



#ifdef CONFIG_X86_32

#include <asm/msr.h>
@@ -80,6 +81,21 @@ enum { 
	IDE_ETC_UDMA_MASK	= 0xc0,

};



/* Some Bachmann OT200 devices have a non working UDMA support due a

 * missing resistor.

 */

static const struct dmi_system_id udma_quirk_dmi_table[] = {

	{

		.ident = "Bachmann electronic OT200",

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "Bachmann electronic"),

			DMI_MATCH(DMI_PRODUCT_NAME, "OT200"),

			DMI_MATCH(DMI_PRODUCT_VERSION, "1")

		},

	},

	{ }

};



static int cs5536_read(struct pci_dev *pdev, int reg, u32 *val)

{

	if (unlikely(use_msr)) {
@@ -242,9 +258,23 @@ static int cs5536_init_one(struct pci_dev *dev, const struct pci_device_id *id) 
		.port_ops = &cs5536_port_ops,

	};



	const struct ata_port_info *ppi[] = { &info, &ata_dummy_port_info };

	static const struct ata_port_info no_udma_info = {

		.flags = ATA_FLAG_SLAVE_POSS,

		.pio_mask = ATA_PIO4,

		.port_ops = &cs5536_port_ops,

	};





	const struct ata_port_info *ppi[2];

	u32 cfg;



	if (dmi_check_system(udma_quirk_dmi_table))

		ppi[0] = &no_udma_info;

	else

		ppi[0] = &info;



	ppi[1] = &ata_dummy_port_info;



	if (use_msr)

		printk(KERN_ERR DRV_NAME ": Using MSR regs instead of PCI\n");

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