Make suspend/resume work with ich chipset in force AHCI mode

Submitted by Joerg Dorchain on Feb. 16, 2011, 9:07 a.m.

Details

Message ID 20110216090709.GR5778@Redstar.dorchain.net
State Not Applicable
Delegated to: David Miller
Headers show

Commit Message

Joerg Dorchain Feb. 16, 2011, 9:07 a.m.
Hello all,

this patch in needed in addition to the previous one make
suspend/resume work in the forced ahci mode.

During resume from suspend to ram, the kernel pci layer restores
the registers for the SATA controller once, then says okay, and
sets dev->state_saved = false. However, since the restore goes
from highest address (the BARs [base address registers]) to
lowest register, some of the higher registers are set as RO
because according to the lower registers controller is in PIIX
mode.  This patch introduces a workaround for
this problem, hacking around the PCI API by setting
pdev->state_saved = true
before we do the restore, basically leaving the pci config space
untouched.

Bye,

Joerg


Signed-off-by: joerg Dorchain<joerg@dorchain.net>

Comments

Sergei Shtylyov Feb. 16, 2011, 11:27 a.m.
Hello.

On 16-02-2011 12:07, Joerg Dorchain wrote:

> Hello all,

> this patch in needed in addition to the previous one make
> suspend/resume work in the forced ahci mode.

    This remark should probably follow --- tear line (after the signoff).

> During resume from suspend to ram, the kernel pci layer restores
> the registers for the SATA controller once, then says okay, and
> sets dev->state_saved = false. However, since the restore goes
> from highest address (the BARs [base address registers]) to
> lowest register, some of the higher registers are set as RO
> because according to the lower registers controller is in PIIX
> mode.  This patch introduces a workaround for
> this problem, hacking around the PCI API by setting
> pdev->state_saved = true
> before we do the restore, basically leaving the pci config space
> untouched.

> Bye,

> Joerg

    "Hello" and "bye" shouldn't be the part of the patch description.

> Signed-off-by: joerg Dorchain<joerg@dorchain.net>

    Need space before the email address.

WBR, Sergei
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Patch hide | download patch | download mbox

--- linux/drivers/ata/ahci.c.orig	2011-02-04 18:13:33.000000000 +0100
+++ linux/drivers/ata/ahci.c	2011-02-11 13:45:22.000000000 +0100
@@ -640,6 +640,11 @@ 
 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
 	int rc;
 
+	/*
+	 * override check to see if PCI config space is already
+	 * restored in pci_restore_state
+	 */
+	pdev->state_saved = true;
 	rc = ata_pci_device_do_resume(pdev);
 	if (rc)
 		return rc;