Re: [PATCH] ata_piix: ignore all zero PCS value on ICH5's

["Jean-François Stenuit" <jfs@keytradebank.com>]

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Hi Tejun,

Back to work this morning. I applied this patch to 2.6.15-rc5 to test my 
problematic HP DL140G2.

Result of the tests :
Reboot 1 : successfull, patch code used
Reboot 2 : successfull, patch code not used
Reboot 3 : successfull, patch code used
Reboot 4 : successfull, patch code not used
Reboot 5 : successfull, patch code used
Cold boot 1 : successfull, patch code used
Cold boot 2 : successfull, patch code not used
Cold boot 3 : successfull, patch code not used
Cold boot 4 : successfull, patch code used
Cold boot 5 : successfull, patch code used

Seems the patch is working.

Tejun Heo wrote:

>Some ICH5's report 0 for PCS even when they have active working ports.
>This patch makes piix_sata_probe() ignore 0 PCS value on ICH5's and
>probe all ports in such cases.  And while at it, remove bogus
>assignment to mask.
>
>Signed-off-by: Tejun Heo <htejun@gmail.com>
>
>--
>
>Hi, Jean-Francois (sorry, cannot type that character) and 0602.
>
>Can you guys please verify that this patch works?  This patch is
>supposed to do the same thing as my previous patch with
>override_PCS=1.
>
>
>diff --git a/drivers/scsi/ata_piix.c b/drivers/scsi/ata_piix.c
>index 887b2b9..482995b 100644
>--- a/drivers/scsi/ata_piix.c
>+++ b/drivers/scsi/ata_piix.c
>@@ -58,6 +58,7 @@ enum {
> 	ICH5_PCS		= 0x92,	/* port control and status */
> 	PIIX_SCC		= 0x0A, /* sub-class code register */
> 
>+	PIIX_FLAG_UNRELIABLE_PCS= (1 << 27), /* PCS bits are unreliable */
> 	PIIX_FLAG_AHCI		= (1 << 28), /* AHCI possible */
> 	PIIX_FLAG_CHECKINTR	= (1 << 29), /* make sure PCI INTx enabled */
> 	PIIX_FLAG_COMBINED	= (1 << 30), /* combined mode possible */
>@@ -223,7 +224,8 @@ static struct ata_port_info piix_port_in
> 	{
> 		.sht		= &piix_sht,
> 		.host_flags	= ATA_FLAG_SATA | ATA_FLAG_SRST |
>-				  PIIX_FLAG_COMBINED | PIIX_FLAG_CHECKINTR,
>+				  PIIX_FLAG_COMBINED | PIIX_FLAG_CHECKINTR |
>+				  PIIX_FLAG_UNRELIABLE_PCS,
> 		.pio_mask	= 0x1f,	/* pio0-4 */
> 		.mwdma_mask	= 0x07, /* mwdma0-2 */
> 		.udma_mask	= 0x7f,	/* udma0-6 */
>@@ -362,12 +364,15 @@ static int piix_sata_probe (struct ata_p
> 	int orig_mask, mask, i;
> 	u8 pcs;
> 
>-	mask = (PIIX_PORT_PRESENT << ap->hard_port_no) |
>-	       (PIIX_PORT_ENABLED << ap->hard_port_no);
>-
> 	pci_read_config_byte(pdev, ICH5_PCS, &pcs);
> 	orig_mask = (int) pcs & 0xff;
> 
>+	if (orig_mask == 0 && ap->flags & PIIX_FLAG_UNRELIABLE_PCS) {
>+		printk(KERN_INFO "ata%u: PIIX PCS reports 0x00, ignoring PCS\n",
>+		       ap->id);
>+		return 1;
>+	}
>+
> 	/* TODO: this is vaguely wrong for ICH6 combined mode,
> 	 * where only two of the four SATA ports are mapped
> 	 * onto a single ATA channel.  It is also vaguely inaccurate
>
>  
>


-- 
Jean-François "Jef" Stenuit
Network & Security manager
Keytrade Bank SA


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