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 <RunaGuo-oc@xxxxxxxxxxx>
---
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 */
