scsi: hisi_sas: service interrupt ITCT_CLR interrupt in v2 hw

This patch is a fix related to freeing a device in v2 hw driver.

Before, we polled to ITCT CLR interrupt to check if a device is free.

This was error prone, as if the interrupt doesn't occur in 10us, we miss
processing it.

To avoid this situation, service this interrupt and sync the event with
a completion.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index ad6b2d18047b29430b4f6ea1c59ca63a4a33f545..23a22dcba15430eb0a21eeaadd72b6f8ee71b527 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -141,6 +141,7 @@ struct hisi_sas_dq {
 struct hisi_sas_device {
        struct hisi_hba         *hisi_hba;
        struct domain_device    *sas_device;
+       struct completion *completion;
        struct hisi_sas_dq      *dq;
        struct list_head        list;
        u64 attached_phy;

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index 9eea0b4e04342c6804551dc3c5365f31f6979c74..0e3634ec1225013418c98d4213e5b0b5e35eef86 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -974,12 +974,14 @@ static void setup_itct_v2_hw(struct hisi_hba *hisi_hba,
 static void free_device_v2_hw(struct hisi_hba *hisi_hba,
                              struct hisi_sas_device *sas_dev)
 {
+       DECLARE_COMPLETION_ONSTACK(completion);
        u64 dev_id = sas_dev->device_id;
-       struct device *dev = hisi_hba->dev;
        struct hisi_sas_itct *itct = &hisi_hba->itct[dev_id];
        u32 reg_val = hisi_sas_read32(hisi_hba, ENT_INT_SRC3);
        int i;
 
+       sas_dev->completion = &completion;
+
        /* SoC bug workaround */
        if (dev_is_sata(sas_dev->sas_device))
                clear_bit(sas_dev->sata_idx, hisi_hba->sata_dev_bitmap);
@@ -989,28 +991,12 @@ static void free_device_v2_hw(struct hisi_hba *hisi_hba,
                hisi_sas_write32(hisi_hba, ENT_INT_SRC3,
                                 ENT_INT_SRC3_ITC_INT_MSK);
 
-       /* clear the itct int*/
        for (i = 0; i < 2; i++) {
-               /* clear the itct table*/
-               reg_val = hisi_sas_read32(hisi_hba, ITCT_CLR);
-               reg_val |= ITCT_CLR_EN_MSK | (dev_id & ITCT_DEV_MSK);
+               reg_val = ITCT_CLR_EN_MSK | (dev_id & ITCT_DEV_MSK);
                hisi_sas_write32(hisi_hba, ITCT_CLR, reg_val);
+               wait_for_completion(sas_dev->completion);
 
-               udelay(10);
-               reg_val = hisi_sas_read32(hisi_hba, ENT_INT_SRC3);
-               if (ENT_INT_SRC3_ITC_INT_MSK & reg_val) {
-                       dev_dbg(dev, "got clear ITCT done interrupt\n");
-
-                       /* invalid the itct state*/
-                       memset(itct, 0, sizeof(struct hisi_sas_itct));
-                       hisi_sas_write32(hisi_hba, ENT_INT_SRC3,
-                                        ENT_INT_SRC3_ITC_INT_MSK);
-
-                       /* clear the itct */
-                       hisi_sas_write32(hisi_hba, ITCT_CLR, 0);
-                       dev_dbg(dev, "clear ITCT ok\n");
-                       break;
-               }
+               memset(itct, 0, sizeof(struct hisi_sas_itct));
        }
 }
 
@@ -1191,7 +1177,7 @@ static void init_reg_v2_hw(struct hisi_hba *hisi_hba)
        hisi_sas_write32(hisi_hba, ENT_INT_SRC3, 0xffffffff);
        hisi_sas_write32(hisi_hba, ENT_INT_SRC_MSK1, 0x7efefefe);
        hisi_sas_write32(hisi_hba, ENT_INT_SRC_MSK2, 0x7efefefe);
-       hisi_sas_write32(hisi_hba, ENT_INT_SRC_MSK3, 0x7ffffffe);
+       hisi_sas_write32(hisi_hba, ENT_INT_SRC_MSK3, 0x7ffe20fe);
        hisi_sas_write32(hisi_hba, SAS_ECC_INTR_MSK, 0xfff00c30);
        for (i = 0; i < hisi_hba->queue_count; i++)
                hisi_sas_write32(hisi_hba, OQ0_INT_SRC_MSK+0x4*i, 0);
@@ -3092,8 +3078,20 @@ static irqreturn_t fatal_axi_int_v2_hw(int irq_no, void *p)
                              irq_value);
                        queue_work(hisi_hba->wq, &hisi_hba->rst_work);
                }
+
+               if (irq_value & BIT(ENT_INT_SRC3_ITC_INT_OFF)) {
+                       u32 reg_val = hisi_sas_read32(hisi_hba, ITCT_CLR);
+                       u32 dev_id = reg_val & ITCT_DEV_MSK;
+                       struct hisi_sas_device *sas_dev =
+                                       &hisi_hba->devices[dev_id];
+
+                       hisi_sas_write32(hisi_hba, ITCT_CLR, 0);
+                       dev_dbg(dev, "clear ITCT ok\n");
+                       complete(sas_dev->completion);
+               }
        }
 
+       hisi_sas_write32(hisi_hba, ENT_INT_SRC3, irq_value);
        hisi_sas_write32(hisi_hba, ENT_INT_SRC_MSK3, irq_msk);
 
        return IRQ_HANDLED;