Commit 37310bad authored by Qi Liu's avatar Qi Liu Committed by Martin K. Petersen
Browse files

scsi: hisi_sas: Fix phyup timeout on FPGA 

The OOB interrupt and phyup interrupt handlers may run out-of-order in high
CPU usage scenarios. Since the hisi_sas_phy.timer is added in
hisi_sas_phy_oob_ready() and disarmed in phy_up_v3_hw(), this out-of-order
execution will cause hisi_sas_phy.timer timeout to trigger.

To solve, protect hisi_sas_phy.timer and .attached with a lock, and ensure
that the timer won't be added after phyup handler completes.

Link: https://lore.kernel.org/r/1639579061-179473-8-git-send-email-john.garry@huawei.com


Signed-off-by: default avatarQi Liu <liuqi115@huawei.com>
Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 16775db6

drivers/scsi/hisi_sas/hisi_sas_main.c

+13 −5
Original line number Diff line number Diff line
@@ -909,10 +909,14 @@ void hisi_sas_phy_oob_ready(struct hisi_hba *hisi_hba, int phy_no) 
{

	struct hisi_sas_phy *phy = &hisi_hba->phy[phy_no];

	struct device *dev = hisi_hba->dev;

	unsigned long flags;



	dev_dbg(dev, "phy%d OOB ready\n", phy_no);

	if (phy->phy_attached)

	spin_lock_irqsave(&phy->lock, flags);

	if (phy->phy_attached) {

		spin_unlock_irqrestore(&phy->lock, flags);

		return;

	}



	if (!timer_pending(&phy->timer)) {

		if (phy->wait_phyup_cnt < HISI_SAS_WAIT_PHYUP_RETRIES) {
@@ -920,13 +924,17 @@ void hisi_sas_phy_oob_ready(struct hisi_hba *hisi_hba, int phy_no) 
			phy->timer.expires = jiffies +

					     HISI_SAS_WAIT_PHYUP_TIMEOUT;

			add_timer(&phy->timer);

		} else {

			spin_unlock_irqrestore(&phy->lock, flags);

			return;

		}



		dev_warn(dev, "phy%d failed to come up %d times, giving up\n",

			 phy_no, phy->wait_phyup_cnt);

		phy->wait_phyup_cnt = 0;

	}

	spin_unlock_irqrestore(&phy->lock, flags);

}

}



EXPORT_SYMBOL_GPL(hisi_sas_phy_oob_ready);



static void hisi_sas_phy_init(struct hisi_hba *hisi_hba, int phy_no)

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

+8 −2
Original line number Diff line number Diff line
@@ -1484,7 +1484,6 @@ static irqreturn_t phy_up_v3_hw(int phy_no, struct hisi_hba *hisi_hba) 
	struct asd_sas_phy *sas_phy = &phy->sas_phy;

	struct device *dev = hisi_hba->dev;



	del_timer(&phy->timer);

	hisi_sas_phy_write32(hisi_hba, phy_no, PHYCTRL_PHY_ENA_MSK, 1);



	port_id = hisi_sas_read32(hisi_hba, PHY_PORT_NUM_MA);
@@ -1561,9 +1560,16 @@ static irqreturn_t phy_up_v3_hw(int phy_no, struct hisi_hba *hisi_hba) 
	}



	phy->port_id = port_id;

	phy->phy_attached = 1;



	hisi_sas_notify_phy_event(phy, HISI_PHYE_PHY_UP);



	res = IRQ_HANDLED;



	spin_lock(&phy->lock);

	/* Delete timer and set phy_attached atomically */

	del_timer(&phy->timer);

	phy->phy_attached = 1;

	spin_unlock(&phy->lock);

end:

	if (phy->reset_completion)

		complete(phy->reset_completion);