Commit a878539e authored by Jeff Garzik's avatar Jeff Garzik
Browse files

ahci: work around ATI SB600 h/w quirk 



This addresses the recent ATI SB600 errata, where the hardware does
not like 256-length PRD entries during FPDMA (aka NCQ).

It hurts performance on SB600, but it is more important to get a
correct patch eliminating the data corruption/lockups, and then later
on tune for performance.

We simply limit each command to a maximum of 255 sectors, on SB600.

Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 6ddd6861

drivers/ata/ahci.c

+13 −1
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ enum { 
	AHCI_HFLAG_NO_MSI		= (1 << 5), /* no PCI MSI */

	AHCI_HFLAG_NO_PMP		= (1 << 6), /* no PMP */

	AHCI_HFLAG_NO_HOTPLUG		= (1 << 7), /* ignore PxSERR.DIAG.N */

	AHCI_HFLAG_SECT255		= (1 << 8), /* max 255 sectors */



	/* ap->flags bits */
@@ -255,6 +256,7 @@ static void ahci_vt8251_error_handler(struct ata_port *ap); 
static void ahci_p5wdh_error_handler(struct ata_port *ap);

static void ahci_post_internal_cmd(struct ata_queued_cmd *qc);

static int ahci_port_resume(struct ata_port *ap);

static void ahci_dev_config(struct ata_device *dev);

static unsigned int ahci_fill_sg(struct ata_queued_cmd *qc, void *cmd_tbl);

static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag,

			       u32 opts);
@@ -294,6 +296,8 @@ static const struct ata_port_operations ahci_ops = { 
	.check_altstatus	= ahci_check_status,

	.dev_select		= ata_noop_dev_select,



	.dev_config		= ahci_dev_config,



	.tf_read		= ahci_tf_read,



	.qc_defer		= sata_pmp_qc_defer_cmd_switch,
@@ -425,7 +429,7 @@ static const struct ata_port_info ahci_port_info[] = { 
	/* board_ahci_sb600 */

	{

		AHCI_HFLAGS	(AHCI_HFLAG_IGN_SERR_INTERNAL |

				 AHCI_HFLAG_32BIT_ONLY | AHCI_HFLAG_NO_PMP),

				 AHCI_HFLAG_SECT255 | AHCI_HFLAG_NO_PMP),

		.flags		= AHCI_FLAG_COMMON,

		.link_flags	= AHCI_LFLAG_COMMON,

		.pio_mask	= 0x1f, /* pio0-4 */
@@ -1176,6 +1180,14 @@ static void ahci_init_controller(struct ata_host *host) 
	VPRINTK("HOST_CTL 0x%x\n", tmp);

}



static void ahci_dev_config(struct ata_device *dev)

{

	struct ahci_host_priv *hpriv = dev->link->ap->host->private_data;



	if (hpriv->flags & AHCI_HFLAG_SECT255)

		dev->max_sectors = 255;

}



static unsigned int ahci_dev_classify(struct ata_port *ap)

{

	void __iomem *port_mmio = ahci_port_base(ap);

CRA Git | Maintained and supported by SUSTech CRA and CCSE