On Wed, 1 Aug 2007 14:16:51 -0700
Kristen Carlson Accardi <[EMAIL PROTECTED]> wrote:

> I was able to duplicate Tejun's problem on an ATAPI device I had here.
> this updated patch fixed my problem.  These devices are just setting 
> PhyReady (N) and CommWake (W) in Serror on power state changes, ignoring
> them seems to be fine, and fixed the problem for me.

Hi Tejun,
Were you able to test out this patch and see if it solved your ATAPI
device/ALPM issues?

Thanks,
Kristen


> 
> 
> Enable Aggressive Link Power management for AHCI controllers.
> 
> This patch will set the correct bits to turn on Aggressive
> Link Power Management (ALPM) for the ahci driver.  This
> will cause the controller and disk to negotiate a lower
> power state for the link when there is no activity (see
> the AHCI 1.x spec for details).  This feature is mutually
> exclusive with Hot Plug, so when ALPM is enabled, Hot Plug
> is disabled.  ALPM will be enabled by default, but it is
> settable via the scsi host syfs interface.  Possible 
> settings for this feature are:
> 
> Setting               Effect
> ----------------------------------------------------------
> min_power     ALPM is enabled, and link set to enter 
>               lowest power state (SLUMBER) when idle
>               Hot plug not allowed.
> 
> max_performance       ALPM is disabled, Hot Plug is allowed
> 
> medium_power  ALPM is enabled, and link set to enter
>               second lowest power state (PARTIAL) when
>               idle.  Hot plug not allowed.
> 
> Signed-off-by:  Kristen Carlson Accardi <[EMAIL PROTECTED]>
> 
> Index: 2.6-git/drivers/ata/ahci.c
> ===================================================================
> --- 2.6-git.orig/drivers/ata/ahci.c
> +++ 2.6-git/drivers/ata/ahci.c
> @@ -48,6 +48,9 @@
>  #define DRV_NAME     "ahci"
>  #define DRV_VERSION  "2.3"
>  
> +static int ahci_enable_alpm(struct ata_port *ap,
> +             enum link_pm policy);
> +static int ahci_disable_alpm(struct ata_port *ap);
>  
>  enum {
>       AHCI_PCI_BAR            = 5,
> @@ -98,6 +101,7 @@ enum {
>       /* HOST_CAP bits */
>       HOST_CAP_SSC            = (1 << 14), /* Slumber capable */
>       HOST_CAP_CLO            = (1 << 24), /* Command List Override support */
> +     HOST_CAP_ALPM           = (1 << 26), /* Aggressive Link PM support */
>       HOST_CAP_SSS            = (1 << 27), /* Staggered Spin-up */
>       HOST_CAP_SNTF           = (1 << 29), /* SNotification register */
>       HOST_CAP_NCQ            = (1 << 30), /* Native Command Queueing */
> @@ -153,6 +157,8 @@ enum {
>                                 PORT_IRQ_PIOS_FIS | PORT_IRQ_D2H_REG_FIS,
>  
>       /* PORT_CMD bits */
> +     PORT_CMD_ASP            = (1 << 27), /* Aggressive Slumber/Partial */
> +     PORT_CMD_ALPE           = (1 << 26), /* Aggressive Link PM enable */
>       PORT_CMD_ATAPI          = (1 << 24), /* Device is ATAPI */
>       PORT_CMD_LIST_ON        = (1 << 15), /* cmd list DMA engine running */
>       PORT_CMD_FIS_ON         = (1 << 14), /* FIS DMA engine running */
> @@ -244,6 +250,11 @@ static int ahci_pci_device_suspend(struc
>  static int ahci_pci_device_resume(struct pci_dev *pdev);
>  #endif
>  
> +static struct class_device_attribute *ahci_shost_attrs[] = {
> +     &class_device_attr_link_power_management_policy,
> +     NULL
> +};
> +
>  static struct scsi_host_template ahci_sht = {
>       .module                 = THIS_MODULE,
>       .name                   = DRV_NAME,
> @@ -261,6 +272,7 @@ static struct scsi_host_template ahci_sh
>       .slave_configure        = ata_scsi_slave_config,
>       .slave_destroy          = ata_scsi_slave_destroy,
>       .bios_param             = ata_std_bios_param,
> +     .shost_attrs            = ahci_shost_attrs,
>  };
>  
>  static const struct ata_port_operations ahci_ops = {
> @@ -292,6 +304,8 @@ static const struct ata_port_operations 
>       .port_suspend           = ahci_port_suspend,
>       .port_resume            = ahci_port_resume,
>  #endif
> +     .enable_pm              = ahci_enable_alpm,
> +     .disable_pm             = ahci_disable_alpm,
>  
>       .port_start             = ahci_port_start,
>       .port_stop              = ahci_port_stop,
> @@ -778,6 +792,156 @@ static void ahci_power_up(struct ata_por
>       writel(cmd | PORT_CMD_ICC_ACTIVE, port_mmio + PORT_CMD);
>  }
>  
> +static int ahci_disable_alpm(struct ata_port *ap)
> +{
> +     void __iomem *port_mmio = ahci_port_base(ap);
> +     u32 cmd, scontrol;
> +     struct ahci_port_priv *pp = ap->private_data;
> +
> +     /*
> +      * disable Interface Power Management State Transitions
> +      * This is accomplished by setting bits 8:11 of the
> +      * SATA Control register
> +      */
> +     scontrol = readl(port_mmio + PORT_SCR_CTL);
> +     scontrol |= (0x3 << 8);
> +     writel(scontrol, port_mmio + PORT_SCR_CTL);
> +
> +     /* get the existing command bits */
> +     cmd = readl(port_mmio + PORT_CMD);
> +
> +     /* disable ALPM and ASP */
> +     cmd &= ~PORT_CMD_ASP;
> +     cmd &= ~PORT_CMD_ALPE;
> +
> +     /* force the interface back to active */
> +     cmd |= PORT_CMD_ICC_ACTIVE;
> +
> +     /* write out new cmd value */
> +     writel(cmd, port_mmio + PORT_CMD);
> +     cmd = readl(port_mmio + PORT_CMD);
> +
> +     /* wait 10ms to be sure we've come out of any low power state */
> +     msleep(10);
> +
> +     /* clear out any PhyRdy stuff from interrupt status */
> +     writel(PORT_IRQ_PHYRDY, port_mmio + PORT_IRQ_STAT);
> +
> +     /* go ahead and clean out PhyRdy Change from Serror too */
> +     ahci_scr_write(ap, SCR_ERROR, ((1 << 16) | (1 << 18)));
> +
> +     /*
> +      * Clear flag to indicate that we should ignore all PhyRdy
> +      * state changes
> +      */
> +     ap->flags &= ~AHCI_FLAG_NO_HOTPLUG;
> +
> +     /*
> +      * Enable interrupts on Phy Ready.
> +      */
> +     pp->intr_mask |= PORT_IRQ_PHYRDY;
> +     writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
> +
> +     /*
> +      * don't change the link pm policy - we can be called
> +      * just to turn of link pm temporarily
> +      */
> +     return 0;
> +}
> +
> +static int ahci_enable_alpm(struct ata_port *ap,
> +     enum link_pm policy)
> +{
> +     struct ahci_host_priv *hpriv = ap->host->private_data;
> +     void __iomem *port_mmio = ahci_port_base(ap);
> +     u32 cmd, scontrol, sstatus;
> +     struct ahci_port_priv *pp = ap->private_data;
> +     u32 asp;
> +
> +     /* Make sure the host is capable of link power management */
> +     if (!(hpriv->cap & HOST_CAP_ALPM)) {
> +             ap->pm_policy = NOT_AVAILABLE;
> +             return -EINVAL;
> +     }
> +
> +     /* make sure we have a device attached */
> +     sstatus = readl(port_mmio + PORT_SCR_STAT);
> +     if (!(sstatus & 0xf00)) {
> +             ap->pm_policy = NOT_AVAILABLE;
> +             return -EINVAL;
> +     }
> +
> +     switch (policy) {
> +     case MAX_PERFORMANCE:
> +     case NOT_AVAILABLE:
> +             /*
> +              * if we came here with NOT_AVAILABLE,
> +              * it just means this is the first time we
> +              * have tried to enable - default to max performance,
> +              * and let the user go to lower power modes on request.
> +              */
> +             ahci_disable_alpm(ap);
> +             ap->pm_policy = MAX_PERFORMANCE;
> +             return 0;
> +     case MIN_POWER:
> +             /* configure HBA to enter SLUMBER */
> +             asp = PORT_CMD_ASP;
> +             break;
> +     case MEDIUM_POWER:
> +             /* configure HBA to enter PARTIAL */
> +             asp = 0;
> +             break;
> +     default:
> +             return -EINVAL;
> +     }
> +     ap->pm_policy = policy;
> +
> +     /*
> +      * Disable interrupts on Phy Ready. This keeps us from
> +      * getting woken up due to spurious phy ready interrupts
> +      * TBD - Hot plug should be done via polling now, is
> +      * that even supported?
> +      */
> +     pp->intr_mask &= ~PORT_IRQ_PHYRDY;
> +     writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
> +
> +     /*
> +      * Set a flag to indicate that we should ignore all PhyRdy
> +      * state changes since these can happen now whenever we
> +      * change link state
> +      */
> +     ap->flags |= AHCI_FLAG_NO_HOTPLUG;
> +
> +     /* get the existing command bits */
> +     cmd = readl(port_mmio + PORT_CMD);
> +
> +     /*
> +      * enable Interface Power Management State Transitions
> +      * This is accomplished by clearing bits 8:11 of the
> +      * SATA Control register
> +      */
> +     scontrol = readl(port_mmio + PORT_SCR_CTL);
> +     scontrol &= ~(0x3 << 8);
> +     writel(scontrol, port_mmio + PORT_SCR_CTL);
> +
> +     /*
> +      * Set ASP based on Policy
> +      */
> +     cmd |= asp;
> +
> +     /*
> +      * Setting this bit will instruct the HBA to aggressively
> +      * enter a lower power link state when it's appropriate and
> +      * based on the value set above for ASP
> +      */
> +     cmd |= PORT_CMD_ALPE;
> +
> +     /* write out new cmd value */
> +     writel(cmd, port_mmio + PORT_CMD);
> +     cmd = readl(port_mmio + PORT_CMD);
> +     return 0;
> +}
> +
>  #ifdef CONFIG_PM
>  static void ahci_power_down(struct ata_port *ap)
>  {
> @@ -1355,6 +1519,17 @@ static void ahci_port_intr(struct ata_po
>       status = readl(port_mmio + PORT_IRQ_STAT);
>       writel(status, port_mmio + PORT_IRQ_STAT);
>  
> +     /* If we are getting PhyRdy, this is
> +      * just a power state change, we should
> +      * clear out this, plus the PhyRdy/Comm
> +      * Wake bits from Serror
> +      */
> +     if ((ap->flags & AHCI_FLAG_NO_HOTPLUG) &&
> +             (status & PORT_IRQ_PHYRDY)) {
> +             status &= ~PORT_IRQ_PHYRDY;
> +             ahci_scr_write(ap, SCR_ERROR, ((1 << 16) | (1 << 18)));
> +     }
> +
>       if (unlikely(status & PORT_IRQ_ERROR)) {
>               ahci_error_intr(ap, status);
>               return;
> @@ -1861,6 +2036,9 @@ static int ahci_init_one(struct pci_dev 
>               struct ata_port *ap = host->ports[i];
>               void __iomem *port_mmio = ahci_port_base(ap);
>  
> +             /* set initial link pm policy */
> +             ap->pm_policy = NOT_AVAILABLE;
> +
>               /* standard SATA port setup */
>               if (hpriv->port_map & (1 << i))
>                       ap->ioaddr.cmd_addr = port_mmio;
-
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