> Date: Tue, 17 May 2016 18:34:19 +0200
> From: Stefan Sperling <[email protected]>
>
> According to a comment in iwlwifi:
>
> * Clearing FH_MEM_RCSR_CHNL0_CONFIG_REG to 0 turns off Rx DMA.
> * Driver should poll FH_MEM_RSSR_RX_STATUS_REG for
> * FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE (bit 24) before continuing.
>
> We missed polling this bit in the init code path. Probably harmless,
> but can be fixed in a simple way by splitting iwm_reset_rx_ring()
> into two functions.
ok kettenis@
> Index: if_iwm.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/if_iwm.c,v
> retrieving revision 1.79
> diff -u -p -r1.79 if_iwm.c
> --- if_iwm.c 13 Apr 2016 10:34:32 -0000 1.79
> +++ if_iwm.c 17 May 2016 16:20:16 -0000
> @@ -235,6 +235,7 @@ void iwm_free_kw(struct iwm_softc *);
> int iwm_alloc_ict(struct iwm_softc *);
> void iwm_free_ict(struct iwm_softc *);
> int iwm_alloc_rx_ring(struct iwm_softc *, struct iwm_rx_ring *);
> +void iwm_disable_rx_dma(struct iwm_softc *);
> void iwm_reset_rx_ring(struct iwm_softc *, struct iwm_rx_ring *);
> void iwm_free_rx_ring(struct iwm_softc *, struct iwm_rx_ring *);
> int iwm_alloc_tx_ring(struct iwm_softc *, struct iwm_tx_ring *, int);
> @@ -1050,7 +1051,7 @@ fail: iwm_free_rx_ring(sc, ring);
> }
>
> void
> -iwm_reset_rx_ring(struct iwm_softc *sc, struct iwm_rx_ring *ring)
> +iwm_disable_rx_dma(struct iwm_softc *sc)
> {
> int ntries;
>
> @@ -1064,6 +1065,11 @@ iwm_reset_rx_ring(struct iwm_softc *sc,
> }
> iwm_nic_unlock(sc);
> }
> +}
> +
> +void
> +iwm_reset_rx_ring(struct iwm_softc *sc, struct iwm_rx_ring *ring)
> +{
> ring->cur = 0;
> bus_dmamap_sync(sc->sc_dmat, ring->stat_dma.map, 0,
> ring->stat_dma.size, BUS_DMASYNC_PREWRITE);
> @@ -1537,6 +1543,7 @@ iwm_stop_device(struct iwm_softc *sc)
> }
> iwm_nic_unlock(sc);
> }
> + iwm_disable_rx_dma(sc);
>
> /* Stop RX ring. */
> iwm_reset_rx_ring(sc, &sc->rxq);
> @@ -1631,7 +1638,7 @@ iwm_nic_rx_init(struct iwm_softc *sc)
> memset(sc->rxq.stat, 0, sizeof(*sc->rxq.stat));
>
> /* stop DMA */
> - IWM_WRITE(sc, IWM_FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
> + iwm_disable_rx_dma(sc);
> IWM_WRITE(sc, IWM_FH_MEM_RCSR_CHNL0_RBDCB_WPTR, 0);
> IWM_WRITE(sc, IWM_FH_MEM_RCSR_CHNL0_FLUSH_RB_REQ, 0);
> IWM_WRITE(sc, IWM_FH_RSCSR_CHNL0_RDPTR, 0);
>
>
