> +void gpr_free_port(gpr_port_t *port) > +{ > + struct packet_router *gpr = port->pr; > + unsigned long flags; > + > + spin_lock_irqsave(&gpr->svcs_lock, flags); > + idr_remove(&gpr->svcs_idr, port->id); > + spin_unlock_irqrestore(&gpr->svcs_lock, flags); maybe add a comment somewhere on why you need the irqsave/irqrestore version of spin_lock/unlock? It's not very clear by looking at this patch only that those locks are handled in interrupt context. > + > + kfree(port); > +} > +EXPORT_SYMBOL_GPL(gpr_free_port); > + > +gpr_port_t *gpr_alloc_port(struct apr_device *gdev, struct device *dev, > + gpr_port_cb cb, void *priv) > +{ > + struct packet_router *pr = dev_get_drvdata(gdev->dev.parent); > + gpr_port_t *port; > + struct pkt_router_svc *svc; > + int id; > + > + port = kzalloc(sizeof(*port), GFP_KERNEL); > + if (!port) > + return ERR_PTR(-ENOMEM); > + > + svc = port; > + svc->callback = cb; > + svc->pr = pr; > + svc->priv = priv; > + svc->dev = dev; > + spin_lock_init(&svc->lock); > + > + spin_lock(&pr->svcs_lock); > + id = idr_alloc_cyclic(&pr->svcs_idr, svc, GPR_DYNAMIC_PORT_START, > + GPR_DYNAMIC_PORT_END, GFP_ATOMIC); > + if (id < 0) { > + dev_err(dev, "Unable to allocate dynamic GPR src port\n"); > + kfree(port); > + spin_unlock(&pr->svcs_lock); nit-pick: more this before the dev_err? > + return ERR_PTR(-ENOMEM); > + } > + > + svc->id = id; > + spin_unlock(&pr->svcs_lock); > + > + dev_info(dev, "Adding GPR src port (%x)\n", svc->id); > + > + return port; > +} > +static int gpr_do_rx_callback(struct packet_router *gpr, struct apr_rx_buf *abuf) > +{ > + uint16_t hdr_size, ver; > + struct pkt_router_svc *svc = NULL; unnecessary init? it's overritten... > + struct gpr_resp_pkt resp; > + struct gpr_hdr *hdr; > + unsigned long flags; > + void *buf = abuf->buf; > + int len = abuf->len; > + > + hdr = buf; > + ver = hdr->version; > + if (ver > GPR_PKT_VER + 1) > + return -EINVAL; > + > + hdr_size = hdr->hdr_size; > + if (hdr_size < GPR_PKT_HEADER_WORD_SIZE) { > + dev_err(gpr->dev, "GPR: Wrong hdr size:%d\n", hdr_size); > + return -EINVAL; > + } > + > + if (hdr->pkt_size < GPR_PKT_HEADER_BYTE_SIZE || hdr->pkt_size != len) { > + dev_err(gpr->dev, "GPR: Wrong packet size\n"); > + return -EINVAL; > + } > + > + resp.hdr = *hdr; > + resp.payload_size = hdr->pkt_size - (hdr_size * 4); > + > + /* > + * NOTE: hdr_size is not same as GPR_HDR_SIZE as remote can include > + * optional headers in to gpr_hdr which should be ignored > + */ > + if (resp.payload_size > 0) > + resp.payload = buf + (hdr_size * 4); > + > + > + spin_lock_irqsave(&gpr->svcs_lock, flags); > + svc = idr_find(&gpr->svcs_idr, hdr->dest_port); ... here > + spin_unlock_irqrestore(&gpr->svcs_lock, flags); > + > + if (!svc) { > + dev_err(gpr->dev, "GPR: Port(%x) is not registered\n", > + hdr->dest_port); > + return -EINVAL; > + } > + > + if (svc->callback) > + svc->callback(&resp, svc->priv, 0); > + > + return 0; > +} > +