Messages in this thread | | | From | Hayes Wang <> | Subject | RE: [PATCH net 1/2] r8152: fix the sw rx checksum is unavailable | Date | Wed, 23 Nov 2016 15:12:21 +0000 |
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Mark Lord [mlord@pobox.com] [...] > What does this code do:
> >static void r8153_set_rx_early_size(struct r8152 *tp) > >{ > > u32 mtu = tp->netdev->mtu; > > u32 ocp_data = (agg_buf_sz - mtu - VLAN_ETH_HLEN - VLAN_HLEN) / 4; > > > > ocp_write_word(tp, MCU_TYPE_USB, USB_RX_EARLY_SIZE, ocp_data); > >}
This only works for RTL8153. However, what you use is RTL8152. It is like delay completion. It is used to reduce the loading of CPU by letting a transfer contain more data to reduce the number of transfers.
> How is ocp_data used by the hardware? > Shouldn't the calculation also include sizeof(rx_desc) in there somewhere?
The algorithm is from our hw engineers, and it should be
(agg_buf_sz - packet size) / 8
You could refer to commit a59e6d815226 ("r8152: correct the rx early size").
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