2022-04-22 00:19:39

by Runa Guo-oc

Subject: [PATCH 1/2] ahci: Add PhyRdy Change control on actual LPM capability

On some platform, when OS enables LPM by default (eg, min_power),
then, PhyRdy Change cannot be detected if ahci supports no LPM.

In ahci spec, PhyRdy Change cannot coexist with LPM.

Adds support to control this case on actual LPM capability.

Signed-off-by: Runa Guo-oc <[email protected]>
---
drivers/ata/ahci.c | 9 +++++++++
drivers/ata/libata-eh.c | 4 ++++
include/linux/libata.h | 4 ++++
3 files changed, 17 insertions(+)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 397dfd2..03f0cb3 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1870,6 +1870,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
else
dev_info(&pdev->dev, "SSS flag set, parallel bus scan disabled\n");

+ if (hpriv->cap & HOST_CAP_PART)
+ host->flags |= ATA_HOST_PART;
+
+ if (hpriv->cap & HOST_CAP_SSC)
+ host->flags |= ATA_HOST_SSC;
+
+ if (hpriv->cap2 & HOST_CAP2_SDS)
+ host->flags |= ATA_HOST_DEVSLP;
+
if (pi.flags & ATA_FLAG_EM)
ahci_reset_em(host);

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 3307ed4..05b1043 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3246,6 +3246,10 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
unsigned int err_mask;
int rc;

+ /* if controller does not support lpm, then sets no LPM flags*/
+ if (!(ap->host->flags & (ATA_HOST_PART | ATA_HOST_SSC | ATA_HOST_DEVSLP)))
+ link->flags |= ATA_LFLAG_NO_LPM;
+
/* if the link or host doesn't do LPM, noop */
if (!IS_ENABLED(CONFIG_SATA_HOST) ||
(link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 732de90..7a243f4 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -216,6 +216,10 @@ enum {
ATA_HOST_PARALLEL_SCAN = (1 << 2), /* Ports on this host can be scanned in parallel */
ATA_HOST_IGNORE_ATA = (1 << 3), /* Ignore ATA devices on this host. */

+ ATA_HOST_PART = (1 << 4), /* Host support partial.*/
+ ATA_HOST_SSC = (1 << 5), /* Host support slumber.*/
+ ATA_HOST_DEVSLP = (1 << 6), /* Host support devslp.*/
+
/* bits 24:31 of host->flags are reserved for LLD specific flags */

/* various lengths of time */
--
2.7.4

2022-04-22 19:37:18

by Runa Guo-oc

Subject: Re: [PATCH 1/2] ahci: Add PhyRdy Change control on actual LPM capability

On 2022/4/21 18:39, Damien Le Moal wrote:
> On 4/21/22 18:43, Runa Guo-oc wrote:
>> On some platform, when OS enables LPM by default (eg, min_power),
>> then, PhyRdy Change cannot be detected if ahci supports no LPM.
> Do you mean "...if the ahci adapter does not support LPM." ?

Yes.

> If that is what you mean, then min_power should not be set.

Yes, I agree with you. But, as we know, link_power_management
is a user policy which can be modified, if some users are not
familiar with ahci spec, then the above case may happen.

> Mario has patches to fix that.


Hmm. How to patch this case ?

>> In ahci spec, PhyRdy Change cannot coexist with LPM.
>>
>> Adds support to control this case on actual LPM capability.
>>
>> Signed-off-by: Runa Guo-oc <[email protected]>
>> ---
>> drivers/ata/ahci.c | 9 +++++++++
>> drivers/ata/libata-eh.c | 4 ++++
>> include/linux/libata.h | 4 ++++
>> 3 files changed, 17 insertions(+)
>>
>> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
>> index 397dfd2..03f0cb3 100644
>> --- a/drivers/ata/ahci.c
>> +++ b/drivers/ata/ahci.c
>> @@ -1870,6 +1870,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>> else
>> dev_info(&pdev->dev, "SSS flag set, parallel bus scan disabled\n");
>>
>> + if (hpriv->cap & HOST_CAP_PART)
>> + host->flags |= ATA_HOST_PART;
>> +
>> + if (hpriv->cap & HOST_CAP_SSC)
>> + host->flags |= ATA_HOST_SSC;
>> +
>> + if (hpriv->cap2 & HOST_CAP2_SDS)
>> + host->flags |= ATA_HOST_DEVSLP;
>> +
>> if (pi.flags & ATA_FLAG_EM)
>> ahci_reset_em(host);
>>
>> diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
>> index 3307ed4..05b1043 100644
>> --- a/drivers/ata/libata-eh.c
>> +++ b/drivers/ata/libata-eh.c
>> @@ -3246,6 +3246,10 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
>> unsigned int err_mask;
>> int rc;
>>
>> + /* if controller does not support lpm, then sets no LPM flags*/
>> + if (!(ap->host->flags & (ATA_HOST_PART | ATA_HOST_SSC | ATA_HOST_DEVSLP)))
>> + link->flags |= ATA_LFLAG_NO_LPM;
>> +
>> /* if the link or host doesn't do LPM, noop */
>> if (!IS_ENABLED(CONFIG_SATA_HOST) ||
>> (link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
>> diff --git a/include/linux/libata.h b/include/linux/libata.h
>> index 732de90..7a243f4 100644
>> --- a/include/linux/libata.h
>> +++ b/include/linux/libata.h
>> @@ -216,6 +216,10 @@ enum {
>> ATA_HOST_PARALLEL_SCAN = (1 << 2), /* Ports on this host can be scanned in parallel */
>> ATA_HOST_IGNORE_ATA = (1 << 3), /* Ignore ATA devices on this host. */
>>
>> + ATA_HOST_PART = (1 << 4), /* Host support partial.*/
>> + ATA_HOST_SSC = (1 << 5), /* Host support slumber.*/
>> + ATA_HOST_DEVSLP = (1 << 6), /* Host support devslp.*/
>> +
>> /* bits 24:31 of host->flags are reserved for LLD specific flags */
>>
>> /* various lengths of time */
>

2022-04-22 20:00:15

by Damien Le Moal

Subject: Re: [PATCH 1/2] ahci: Add PhyRdy Change control on actual LPM capability

On 4/21/22 18:43, Runa Guo-oc wrote:
> On some platform, when OS enables LPM by default (eg, min_power),
> then, PhyRdy Change cannot be detected if ahci supports no LPM.

Do you mean "...if the ahci adapter does not support LPM." ?
If that is what you mean, then min_power should not be set. Mario has
patches to fix that.

>
> In ahci spec, PhyRdy Change cannot coexist with LPM.
>
> Adds support to control this case on actual LPM capability.
>
> Signed-off-by: Runa Guo-oc <[email protected]>
> ---
> drivers/ata/ahci.c | 9 +++++++++
> drivers/ata/libata-eh.c | 4 ++++
> include/linux/libata.h | 4 ++++
> 3 files changed, 17 insertions(+)
>
> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> index 397dfd2..03f0cb3 100644
> --- a/drivers/ata/ahci.c
> +++ b/drivers/ata/ahci.c
> @@ -1870,6 +1870,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> else
> dev_info(&pdev->dev, "SSS flag set, parallel bus scan disabled\n");
>
> + if (hpriv->cap & HOST_CAP_PART)
> + host->flags |= ATA_HOST_PART;
> +
> + if (hpriv->cap & HOST_CAP_SSC)
> + host->flags |= ATA_HOST_SSC;
> +
> + if (hpriv->cap2 & HOST_CAP2_SDS)
> + host->flags |= ATA_HOST_DEVSLP;
> +
> if (pi.flags & ATA_FLAG_EM)
> ahci_reset_em(host);
>
> diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
> index 3307ed4..05b1043 100644
> --- a/drivers/ata/libata-eh.c
> +++ b/drivers/ata/libata-eh.c
> @@ -3246,6 +3246,10 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
> unsigned int err_mask;
> int rc;
>
> + /* if controller does not support lpm, then sets no LPM flags*/
> + if (!(ap->host->flags & (ATA_HOST_PART | ATA_HOST_SSC | ATA_HOST_DEVSLP)))
> + link->flags |= ATA_LFLAG_NO_LPM;
> +
> /* if the link or host doesn't do LPM, noop */
> if (!IS_ENABLED(CONFIG_SATA_HOST) ||
> (link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 732de90..7a243f4 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -216,6 +216,10 @@ enum {
> ATA_HOST_PARALLEL_SCAN = (1 << 2), /* Ports on this host can be scanned in parallel */
> ATA_HOST_IGNORE_ATA = (1 << 3), /* Ignore ATA devices on this host. */
>
> + ATA_HOST_PART = (1 << 4), /* Host support partial.*/
> + ATA_HOST_SSC = (1 << 5), /* Host support slumber.*/
> + ATA_HOST_DEVSLP = (1 << 6), /* Host support devslp.*/
> +
> /* bits 24:31 of host->flags are reserved for LLD specific flags */
>
> /* various lengths of time */


--
Damien Le Moal
Western Digital Research