Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (27 commits)
  pata_atiixp: Don't disable
  sata_inic162x: update intro comment, up the version and drop EXPERIMENTAL
  sata_inic162x: add cardbus support
  sata_inic162x: kill now unused SFF related stuff
  sata_inic162x: use IDMA for ATAPI commands
  sata_inic162x: use IDMA for non DMA ATA commands
  sata_inic162x: kill now unused bmdma related stuff
  sata_inic162x: use IDMA for ATA_PROT_DMA
  sata_inic162x: update TF read handling
  sata_inic162x: add / update constants
  sata_inic162x: misc clean ups
  sata_mv use hweight16() for bit counting (V2)
  sata_mv NCQ-EH for FIS-based switching
  sata_mv delayed eh handling
  libata: export ata_eh_analyze_ncq_error
  sata_mv new mv_port_intr function
  sata_mv fix mv_host_intr bug for hc_irq_cause
  sata_mv NCQ and SError fixes for mv_err_intr
  sata_mv rearrange mv_config_fbs
  sata_mv errata workaround for sata25 part 1
  ...

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index ea2c7649d39..a9027b8fbdd 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -1348,6 +1348,8 @@ static void __devinit piix_init_sidpr(struct ata_host *host)
 {
 	struct pci_dev *pdev = to_pci_dev(host->dev);
 	struct piix_host_priv *hpriv = host->private_data;
+	struct ata_device *dev0 = &host->ports[0]->link.device[0];
+	u32 scontrol;
 	int i;
 
 	/* check for availability */
@@ -1366,6 +1368,29 @@ static void __devinit piix_init_sidpr(struct ata_host *host)
 		return;
 
 	hpriv->sidpr = pcim_iomap_table(pdev)[PIIX_SIDPR_BAR];
+
+	/* SCR access via SIDPR doesn't work on some configurations.
+	 * Give it a test drive by inhibiting power save modes which
+	 * we'll do anyway.
+	 */
+	scontrol = piix_sidpr_read(dev0, SCR_CONTROL);
+
+	/* if IPM is already 3, SCR access is probably working.  Don't
+	 * un-inhibit power save modes as BIOS might have inhibited
+	 * them for a reason.
+	 */
+	if ((scontrol & 0xf00) != 0x300) {
+		scontrol |= 0x300;
+		piix_sidpr_write(dev0, SCR_CONTROL, scontrol);
+		scontrol = piix_sidpr_read(dev0, SCR_CONTROL);
+
+		if ((scontrol & 0xf00) != 0x300) {
+			dev_printk(KERN_INFO, host->dev, "SCR access via "
+				   "SIDPR is available but doesn't work\n");
+			return;
+		}
+	}
+
 	host->ports[0]->ops = &piix_sidpr_sata_ops;
 	host->ports[1]->ops = &piix_sidpr_sata_ops;
 }