From af06b628a6bde8506bbad32dbf7cc641c0176ad7 Mon Sep 17 00:00:00 2001 From: Lang Cheng Date: Sat, 13 Mar 2021 10:30:11 +0800 Subject: [PATCH] RDMA/hns: Fix bug during CMDQ initialization When reloading driver, the head/tail pointer of CMDQ may be not at position 0. Then during initialization of CMDQ, if head is reset first, the firmware will start to handle CMDQ because the head is not equal to the tail. The driver can reset tail first since the firmware will be triggerred only by head. This bug is introduced by changing macros of head/tail register without changing the order of initialization. Fixes: 292b3352bd5b ("RDMA/hns: Adjust fields and variables about CMDQ tail/head") Link: https://lore.kernel.org/r/1615602611-7963-1-git-send-email-liweihang@huawei.com Signed-off-by: Lang Cheng Signed-off-by: Weihang Li Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c index c3934abeb260..ce26f97b2ca2 100644 --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c @@ -1194,8 +1194,10 @@ static void hns_roce_cmq_init_regs(struct hns_roce_dev *hr_dev, bool ring_type) upper_32_bits(dma)); roce_write(hr_dev, ROCEE_TX_CMQ_DEPTH_REG, (u32)ring->desc_num >> HNS_ROCE_CMQ_DESC_NUM_S); - roce_write(hr_dev, ROCEE_TX_CMQ_HEAD_REG, 0); + + /* Make sure to write tail first and then head */ roce_write(hr_dev, ROCEE_TX_CMQ_TAIL_REG, 0); + roce_write(hr_dev, ROCEE_TX_CMQ_HEAD_REG, 0); } else { roce_write(hr_dev, ROCEE_RX_CMQ_BASEADDR_L_REG, (u32)dma); roce_write(hr_dev, ROCEE_RX_CMQ_BASEADDR_H_REG, -- 2.39.5