Re: [PATCH for-rc v2] RDMA/bnxt_re: Fix error recovery sequence

[Leon Romanovsky <leon@kernel.org>]

On Fri, Dec 20, 2024 at 01:29:20PM +0530, Kalesh AP wrote:
> Fixed to return ENXIO from __send_message_basic_sanity()
> to indicate that device is in error state. In the case of
> ERR_DEVICE_DETACHED state, the driver should not post the
> commands to the firmware as it will time out eventually.
> 
> Removed bnxt_re_modify_qp() call from bnxt_re_dev_stop()
> as it is a no-op.
> 
> Fixes: cc5b9b48d447 ("RDMA/bnxt_re: Recover the device when FW error is detected")
> Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
> Reviewed-by: Selvin Xavier <selvin.xavier@broadcom.com>
> ---
> V2: No changes since v1 and is just a resend.
> V1: https://patchwork.kernel.org/project/linux-rdma/patch/20241204075416.478431-5-kalesh-anakkur.purayil@broadcom.com/
> ---
>  drivers/infiniband/hw/bnxt_re/main.c       | 8 +-------
>  drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 7 ++++---
>  drivers/infiniband/hw/bnxt_re/qplib_rcfw.h | 3 +++
>  3 files changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c
> index b7af0d5ff3b6..c143f273b759 100644
> --- a/drivers/infiniband/hw/bnxt_re/main.c
> +++ b/drivers/infiniband/hw/bnxt_re/main.c
> @@ -1715,11 +1715,8 @@ static bool bnxt_re_is_qp1_or_shadow_qp(struct bnxt_re_dev *rdev,
>  
>  static void bnxt_re_dev_stop(struct bnxt_re_dev *rdev)
>  {
> -	int mask = IB_QP_STATE;
> -	struct ib_qp_attr qp_attr;
>  	struct bnxt_re_qp *qp;
>  
> -	qp_attr.qp_state = IB_QPS_ERR;
>  	mutex_lock(&rdev->qp_lock);
>  	list_for_each_entry(qp, &rdev->qp_list, list) {
>  		/* Modify the state of all QPs except QP1/Shadow QP */
> @@ -1727,12 +1724,9 @@ static void bnxt_re_dev_stop(struct bnxt_re_dev *rdev)
>  			if (qp->qplib_qp.state !=
>  			    CMDQ_MODIFY_QP_NEW_STATE_RESET &&
>  			    qp->qplib_qp.state !=
> -			    CMDQ_MODIFY_QP_NEW_STATE_ERR) {
> +			    CMDQ_MODIFY_QP_NEW_STATE_ERR)
>  				bnxt_re_dispatch_event(&rdev->ibdev, &qp->ib_qp,
>  						       1, IB_EVENT_QP_FATAL);
> -				bnxt_re_modify_qp(&qp->ib_qp, &qp_attr, mask,
> -						  NULL);
> -			}
>  		}
>  	}
>  	mutex_unlock(&rdev->qp_lock);
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> index 5e90ea232de8..c8e65169f58a 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> @@ -423,8 +423,9 @@ static int __send_message_basic_sanity(struct bnxt_qplib_rcfw *rcfw,
>  	cmdq = &rcfw->cmdq;
>  
>  	/* Prevent posting if f/w is not in a state to process */
> -	if (test_bit(ERR_DEVICE_DETACHED, &rcfw->cmdq.flags))
> -		return bnxt_qplib_map_rc(opcode);
> +	if (RCFW_NO_FW_ACCESS(rcfw))
> +		return -ENXIO;
> +
>  	if (test_bit(FIRMWARE_STALL_DETECTED, &cmdq->flags))
>  		return -ETIMEDOUT;
>  
> @@ -493,7 +494,7 @@ static int __bnxt_qplib_rcfw_send_message(struct bnxt_qplib_rcfw *rcfw,
>  
>  	rc = __send_message_basic_sanity(rcfw, msg, opcode);
>  	if (rc)
> -		return rc;
> +		return rc == -ENXIO ? bnxt_qplib_map_rc(opcode) : rc;
>  
>  	rc = __send_message(rcfw, msg, opcode);
>  	if (rc)
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> index 88814cb3aa74..4f7d800e35c3 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> @@ -129,6 +129,9 @@ static inline u32 bnxt_qplib_set_cmd_slots(struct cmdq_base *req)
>  
>  #define RCFW_MAX_COOKIE_VALUE		(BNXT_QPLIB_CMDQE_MAX_CNT - 1)
>  #define RCFW_CMD_IS_BLOCKING		0x8000
> +#define RCFW_NO_FW_ACCESS(rcfw)						\
> +	(test_bit(ERR_DEVICE_DETACHED, &(rcfw)->cmdq.flags) ||		\
> +	 pci_channel_offline((rcfw)->pdev))

You promised me that this patch handles races, so how is this
pci_channel_offline() check protected?

Thansk

>  
>  #define HWRM_VERSION_DEV_ATTR_MAX_DPI  0x1000A0000000DULL
>  /* HWRM version 1.10.3.18 */
> -- 
> 2.43.5
>