libata: issue DIPM enable commands with LPM state updated (e5005b15) · Commits · 戴 / test

Low level drivers may behave differently depending on the current link->lpm_policy. During ata_eh_set_lpm(), DIPM enable commands are issued after the successful completion of ap->ops->set_lpm(), which means that the controller is already in the target state. This causes DIPM enable commands to be processed with mismatching controller power state and link->lpm_policy value. In ahci, link->lpm_policy is used to ignore certain PHY events if LPM is enabled; however, as DIPM commands are issued with stale link->lpm_policy, they sometimes end up triggering these conditions and get aborted leading to LPM configuration failure. Fix it by updating link->lpm_policy before issuing DIPM enable commands. Signed-off-by:

Tejun Heo <tj@kernel.org> Reported-by:

Kyle McMartin <kyle@mcmartin.ca> Cc: stable@kernel.org Signed-off-by:

Jeff Garzik <jgarzik@redhat.com>

drivers/ata/libata-eh.c

+14 −3

Original line number	Diff line number	Diff line
		@@ -3275,6 +3275,7 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
		struct ata_port *ap = ata_is_host_link(link) ? link->ap : NULL;
		struct ata_eh_context *ehc = &link->eh_context;
		struct ata_device dev, link_dev = NULL, *lpm_dev = NULL;
		enum ata_lpm_policy old_policy = link->lpm_policy;
		unsigned int hints = ATA_LPM_EMPTY \| ATA_LPM_HIPM;
		unsigned int err_mask;
		int rc;
		@@ -3338,6 +3339,14 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
		goto fail;
		}

		/*
		* Low level driver acked the transition. Issue DIPM command
		* with the new policy set.
		*/
		link->lpm_policy = policy;
		if (ap && ap->slave_link)
		ap->slave_link->lpm_policy = policy;

		/* host config updated, enable DIPM if transitioning to MIN_POWER */
		ata_for_each_dev(dev, link, ENABLED) {
		if (policy == ATA_LPM_MIN_POWER && ata_id_has_dipm(dev->id)) {
		@@ -3353,12 +3362,14 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
		}
		}

		link->lpm_policy = policy;
		if (ap && ap->slave_link)
		ap->slave_link->lpm_policy = policy;
		return 0;

		fail:
		/* restore the old policy */
		link->lpm_policy = old_policy;
		if (ap && ap->slave_link)
		ap->slave_link->lpm_policy = old_policy;

		/* if no device or only one more chance is left, disable LPM */
		if (!dev \|\| ehc->tries[dev->devno] <= 2) {
		ata_link_printk(link, KERN_WARNING,

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