Re: [PATCH 5/8] RDMA/bng_re: Add infrastructure for enabling Firmware channel

[Leon Romanovsky <leonro@nvidia.com>]

On Mon, Sep 15, 2025 at 02:14:19PM +0530, Siva Reddy Kallam wrote:
> On Fri, Sep 12, 2025 at 2:09 PM Simon Horman <horms@kernel.org> wrote:
> >
> > On Fri, Aug 29, 2025 at 12:30:39PM +0000, Siva Reddy Kallam wrote:
> > > Add infrastructure for enabling Firmware channel.
> > >
> > > Signed-off-by: Siva Reddy Kallam <siva.kallam@broadcom.com>
> > > Reviewed-by: Usman Ansari <usman.ansari@broadcom.com>
> >
> > ...
> >
> > > diff --git a/drivers/infiniband/hw/bng_re/bng_fw.c b/drivers/infiniband/hw/bng_re/bng_fw.c
> >
> > ...
> >
> > > +/* function events */
> > > +static int bng_re_process_func_event(struct bng_re_rcfw *rcfw,
> > > +                                  struct creq_func_event *func_event)
> > > +{
> > > +     int rc;
> > > +
> > > +     switch (func_event->event) {
> > > +     case CREQ_FUNC_EVENT_EVENT_TX_WQE_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_TX_DATA_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_RX_WQE_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_RX_DATA_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_CQ_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_TQM_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_CFCQ_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_CFCS_ERROR:
> > > +             /* SRQ ctx error, call srq_handler??
> > > +              * But there's no SRQ handle!
> > > +              */
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_CFCC_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_CFCM_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_TIM_ERROR:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_VF_COMM_REQUEST:
> > > +             break;
> > > +     case CREQ_FUNC_EVENT_EVENT_RESOURCE_EXHAUSTED:
> > > +             break;
> > > +     default:
> > > +             return -EINVAL;
> > > +     }
> > > +
> > > +     return rc;
> >
> > rc does not appear to be initialised in this function.
> >
> > Flagged by Clang 20.1.8 with -Wuninitialized
> 
> Thank you for the review. We will fix it in the next version of the patchset.

Once you are fixing it, please squeeze you switch-case to be something
like that:

switch (func_event->event) {
     case CREQ_FUNC_EVENT_EVENT_TX_WQE_ERROR:
     case CREQ_FUNC_EVENT_EVENT_TX_DATA_ERROR:
     case CREQ_FUNC_EVENT_EVENT_RX_WQE_ERROR:
     ....
     	break;
     default:
     	return -EINVAL;
    }

Thanks

> 
> >
> > > +}
> >
> > ...
> >
> > > +int bng_re_enable_fw_channel(struct bng_re_rcfw *rcfw,
> > > +                          int msix_vector,
> > > +                          int cp_bar_reg_off)
> > > +{
> > > +     struct bng_re_cmdq_ctx *cmdq;
> > > +     struct bng_re_creq_ctx *creq;
> > > +     int rc;
> > > +
> > > +     cmdq = &rcfw->cmdq;
> > > +     creq = &rcfw->creq;
> >
> > Conversely, creq is initialised here but otherwise unused in this function.
> >
> > Flagged by GCC 15.1.0 and Clang 20.1.8 with -Wunused-but-set-variable
> 
> Thank you for the review. We will fix it in the next version of the patchset.
> 
> >
> > > +
> > > +     /* Assign defaults */
> > > +     cmdq->seq_num = 0;
> > > +     set_bit(FIRMWARE_FIRST_FLAG, &cmdq->flags);
> > > +     init_waitqueue_head(&cmdq->waitq);
> > > +
> > > +     rc = bng_re_map_cmdq_mbox(rcfw);
> > > +     if (rc)
> > > +             return rc;
> > > +
> > > +     rc = bng_re_map_creq_db(rcfw, cp_bar_reg_off);
> > > +     if (rc)
> > > +             return rc;
> > > +
> > > +     rc = bng_re_rcfw_start_irq(rcfw, msix_vector, true);
> > > +     if (rc) {
> > > +             dev_err(&rcfw->pdev->dev,
> > > +                     "Failed to request IRQ for CREQ rc = 0x%x\n", rc);
> > > +             bng_re_disable_rcfw_channel(rcfw);
> > > +             return rc;
> > > +     }
> > > +
> > > +     return 0;
> > > +}
> >
> > ...
>