From d2fc401e47529d9ffd2673a5395d56002e31ad98 Mon Sep 17 00:00:00 2001 From: Xiaofei Tan Date: Thu, 31 May 2018 20:50:44 +0800 Subject: [PATCH] scsi: hisi_sas: Fix the conflict between dev gone and host reset There is a possible conflict when a device is removed and host reset occurs concurrently. The reason is that then the device is notified as gone, we try to clear the ITCT, which is notified via an interrupt. The dev gone function pends on this event with a completion, which is completed when the ITCT interrupt occurs. But host reset will disable all interrupts, the wait_for_completion() may wait indefinitely. This patch adds an semaphore to synchronise this two processes. The semaphore is taken by the host reset as the basis of synchronising. Signed-off-by: Xiaofei Tan Signed-off-by: John Garry Signed-off-by: Martin K. Petersen --- drivers/scsi/hisi_sas/hisi_sas.h | 1 + drivers/scsi/hisi_sas/hisi_sas_main.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h index 7052a5d45f7f9..78e5a9254143f 100644 --- a/drivers/scsi/hisi_sas/hisi_sas.h +++ b/drivers/scsi/hisi_sas/hisi_sas.h @@ -277,6 +277,7 @@ struct hisi_hba { int n_phy; spinlock_t lock; + struct semaphore sem; struct timer_list timer; struct workqueue_struct *wq; diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index 1c424bb363fd5..823386ff940cc 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -914,7 +914,9 @@ static void hisi_sas_dev_gone(struct domain_device *device) hisi_sas_dereg_device(hisi_hba, device); + down(&hisi_hba->sem); hisi_hba->hw->clear_itct(hisi_hba, sas_dev); + up(&hisi_hba->sem); device->lldd_dev = NULL; } @@ -1364,6 +1366,7 @@ static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba) if (test_and_set_bit(HISI_SAS_RESET_BIT, &hisi_hba->flags)) return -1; + down(&hisi_hba->sem); dev_info(dev, "controller resetting...\n"); old_state = hisi_hba->hw->get_phys_state(hisi_hba); @@ -1378,6 +1381,7 @@ static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba) if (rc) { dev_warn(dev, "controller reset failed (%d)\n", rc); clear_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags); + up(&hisi_hba->sem); scsi_unblock_requests(shost); goto out; } @@ -1388,6 +1392,7 @@ static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba) hisi_hba->hw->phys_init(hisi_hba); msleep(1000); hisi_sas_refresh_port_id(hisi_hba); + up(&hisi_hba->sem); if (hisi_hba->reject_stp_links_msk) hisi_sas_terminate_stp_reject(hisi_hba); @@ -2016,6 +2021,7 @@ int hisi_sas_alloc(struct hisi_hba *hisi_hba, struct Scsi_Host *shost) struct device *dev = hisi_hba->dev; int i, s, max_command_entries = hisi_hba->hw->max_command_entries; + sema_init(&hisi_hba->sem, 1); spin_lock_init(&hisi_hba->lock); for (i = 0; i < hisi_hba->n_phy; i++) { hisi_sas_phy_init(hisi_hba, i); -- 2.30.2