[LEDE-DEV] MT7621 support Jumbo frames

Wed Apr 19 01:18:59 PDT 2017

Wow, this is perfect. Thank you very much. I will try to use this
patch and compile my own image with up to 2kb frame support. Do you
have any plans on submitting this as a PR to the LEDE git?

On Wed, Apr 19, 2017 at 9:32 AM, Gaetano Catalli
<gaetano.catalli at gmail.com> wrote:
> I've been working on this for a while. Apparently the embedded 5-port
> gigabit switch is able to handle packets with size up to 15KB. On the
> contrary, the GMAC, to which the switch is attached, has a limit of
> 2KB. The following is a patch that changes the max recv frame length
> to 2KB and allows to set the MTU up to that value. It is based on
> kernel 4.4.7.
>
> Signed-off-by: Gaetano Catalli <gaetano.catalli at gmail.com>
> ---
>  drivers/net/ethernet/mediatek/gsw_mt7620.h  |  6 +++++
>  drivers/net/ethernet/mediatek/gsw_mt7621.c  | 13 +++++++----
>  drivers/net/ethernet/mediatek/mtk_eth_soc.c | 36 ++++++++++++++++++-----------
>  drivers/net/ethernet/mediatek/mtk_eth_soc.h |  1 +
>  drivers/net/ethernet/mediatek/soc_mt7621.c  |  2 +-
>  5 files changed, 39 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/net/ethernet/mediatek/gsw_mt7620.h
> b/drivers/net/ethernet/mediatek/gsw_mt7620.h
> index dcef9a8..ce3cd10 100644
> --- a/drivers/net/ethernet/mediatek/gsw_mt7620.h
> +++ b/drivers/net/ethernet/mediatek/gsw_mt7620.h
> @@ -45,6 +45,12 @@
>  #define GSW_REG_ISR 0x700c
>  #define GSW_REG_GPC1 0x7014
>
> +#define GSW_REG_MAC_P0_MCR 0x100
> +#define GSW_REG_MAC_P1_MCR 0x200
> +
> +// Global MAC control register
> +#define GSW_REG_GMACCR 0x30E0
> +
>  #define SYSC_REG_CHIP_REV_ID 0x0c
>  #define SYSC_REG_CFG1 0x14
>  #define RST_CTRL_MCM BIT(2)
> diff --git a/drivers/net/ethernet/mediatek/gsw_mt7621.c
> b/drivers/net/ethernet/mediatek/gsw_mt7621.c
> index 96280b4..db5d56d 100644
> --- a/drivers/net/ethernet/mediatek/gsw_mt7621.c
> +++ b/drivers/net/ethernet/mediatek/gsw_mt7621.c
> @@ -99,17 +99,20 @@ static void mt7621_hw_init(struct mt7620_gsw *gsw,
> struct device_node *np)
>   usleep_range(10, 20);
>
>   if ((rt_sysc_r32(SYSC_REG_CHIP_REV_ID) & 0xFFFF) == 0x0101) {
> - /* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 1536) */
> - mtk_switch_w32(gsw, 0x2105e30b, 0x100);
> + /* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 2k) */
> + mtk_switch_w32(gsw, 0x2305e30b, GSW_REG_MAC_P0_MCR);
>   mt7530_mdio_w32(gsw, 0x3600, 0x5e30b);
>   } else {
> - /* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 1536) */
> - mtk_switch_w32(gsw, 0x2105e33b, 0x100);
> + /* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 2k) */
> + mtk_switch_w32(gsw, 0x2305e33b, GSW_REG_MAC_P0_MCR);
>   mt7530_mdio_w32(gsw, 0x3600, 0x5e33b);
>   }
>
>   /* (GE2, Link down) */
> - mtk_switch_w32(gsw, 0x8000, 0x200);
> + mtk_switch_w32(gsw, 0x8000, GSW_REG_MAC_P1_MCR);
> +
> + /* Set switch max RX frame length to 2k */
> + mt7530_mdio_w32(gsw, GSW_REG_GMACCR, 0x3F0B);
>
>   /* Enable Port 6, P5 as GMAC5, P5 disable */
>   val = mt7530_mdio_r32(gsw, 0x7804);
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index 48eda44..5edafa6 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -37,7 +37,7 @@
>  #include "mdio.h"
>  #include "ethtool.h"
>
> -#define MAX_RX_LENGTH 1536
> +#define MAX_RX_LENGTH 2048
>  #define FE_RX_ETH_HLEN (VLAN_ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN)
>  #define FE_RX_HLEN (NET_SKB_PAD + FE_RX_ETH_HLEN + NET_IP_ALIGN)
>  #define DMA_DUMMY_DESC 0xffffffff
> @@ -1358,11 +1358,29 @@ static int fe_do_ioctl(struct net_device *dev,
> struct ifreq *ifr, int cmd)
>   return -EOPNOTSUPP;
>  }
>
> +static int fe_set_mtu(struct fe_priv* priv, int new_mtu)
> +{
> + int frag_size = fe_max_frag_size(new_mtu);
> + u32 fwd_cfg;
> +
> + fe_stop(priv->netdev);
> + fwd_cfg = fe_r32(FE_GDMA1_FWD_CFG);
> + if (new_mtu <= ETH_DATA_LEN) {
> + fwd_cfg &= ~FE_GDM1_JMB_EN;
> + } else {
> + fwd_cfg &= ~(FE_GDM1_JMB_LEN_MASK << FE_GDM1_JMB_LEN_SHIFT);
> + fwd_cfg |= (DIV_ROUND_UP(frag_size, 1024) <<
> + FE_GDM1_JMB_LEN_SHIFT) | FE_GDM1_JMB_EN;
> + }
> + fe_w32(fwd_cfg, FE_GDMA1_FWD_CFG);
> +
> + return fe_open(priv->netdev);
> +}
> +
>  static int fe_change_mtu(struct net_device *dev, int new_mtu)
>  {
>   struct fe_priv *priv = netdev_priv(dev);
>   int frag_size, old_mtu;
> - u32 fwd_cfg;
>
>   if (!(priv->flags & FE_FLAG_JUMBO_FRAME))
>   return eth_change_mtu(dev, new_mtu);
> @@ -1389,18 +1407,10 @@ static int fe_change_mtu(struct net_device
> *dev, int new_mtu)
>   if (!netif_running(dev))
>   return 0;
>
> - fe_stop(dev);
> - fwd_cfg = fe_r32(FE_GDMA1_FWD_CFG);
> - if (new_mtu <= ETH_DATA_LEN) {
> - fwd_cfg &= ~FE_GDM1_JMB_EN;
> - } else {
> - fwd_cfg &= ~(FE_GDM1_JMB_LEN_MASK << FE_GDM1_JMB_LEN_SHIFT);
> - fwd_cfg |= (DIV_ROUND_UP(frag_size, 1024) <<
> - FE_GDM1_JMB_LEN_SHIFT) | FE_GDM1_JMB_EN;
> - }
> - fe_w32(fwd_cfg, FE_GDMA1_FWD_CFG);
> + if (priv->soc->set_mtu)
> + return priv->soc->set_mtu(priv, new_mtu);
>
> - return fe_open(dev);
> + return fe_set_mtu(priv, new_mtu);
>  }
>
>  static const struct net_device_ops fe_netdev_ops = {
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> index d5f8b87..3acc2c1 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> @@ -381,6 +381,7 @@ struct fe_soc_data {
>   void (*reset_fe)(void);
>   void (*set_mac)(struct fe_priv *priv, unsigned char *mac);
>   int (*fwd_config)(struct fe_priv *priv);
> + int (*set_mtu)(struct fe_priv *priv, int new_mtu);
>   void (*tx_dma)(struct fe_tx_dma *txd);
>   int (*switch_init)(struct fe_priv *priv);
>   int (*switch_config)(struct fe_priv *priv);
> diff --git a/drivers/net/ethernet/mediatek/soc_mt7621.c
> b/drivers/net/ethernet/mediatek/soc_mt7621.c
> index 1609a3e..f95c354 100644
> --- a/drivers/net/ethernet/mediatek/soc_mt7621.c
> +++ b/drivers/net/ethernet/mediatek/soc_mt7621.c
> @@ -140,7 +140,7 @@ static void mt7621_init_data(struct fe_soc_data *data,
>
>   priv->flags = FE_FLAG_PADDING_64B | FE_FLAG_RX_2B_OFFSET |
>   FE_FLAG_RX_SG_DMA | FE_FLAG_NAPI_WEIGHT |
> - FE_FLAG_HAS_SWITCH;
> + FE_FLAG_HAS_SWITCH | FE_FLAG_JUMBO_FRAME;
>
>   netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
>   NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_SG | NETIF_F_TSO |
> --
> 2.7.4
>
> On Mon, Apr 10, 2017 at 9:21 AM, Jaap Buurman <jaapbuurman at gmail.com> wrote:
>> I am able to test this on my DIR-860l. I could try to compile my own
>> build to test this, but I am no C programmer myself. Am I correct in
>> the following post about how to set the flag to allow for jumbo frames
>> to be set?: https://forum.lede-project.org/t/build-for-the-d-link-dir-860l/948/40?u=mushoz
>> If so, I will be able to apply the patch myself and test it. I could
>> then send a PR if the tests are successful.
>>
>> Yours sincerely,
>>
>> Jaap Buurman
>>
>> On Mon, Apr 10, 2017 at 9:16 AM, Milan Kočvara <milankocvara at gmail.com> wrote:
>>> Hello all,
>>> if someone do a testing patch for jumboFrames, I can lend a helping
>>> hand with testing on EdgeRouter X. I think MT7621 know JumboFrames,
>>> because of Ubiquiti FMW allow to set MTU 1536B
>>>
>>> 2017-04-10 2:06 GMT+02:00  <rosenp at gmail.com>:
>>>> Probably was not in the interest of the driver writers. Based on the
>>>> copyrights though, it's mostly LEDE/OpenWRT developers. Try modifying
>>>> the code to test if jumbo frames work.
>>>>
>>>> On Sun, 2017-04-09 at 21:20 +0200, Jaap Buurman wrote:
>>>>> Hello all,
>>>>>
>>>>> I found the message below in a conversation from back in August, 2016
>>>>> in this mailinglist. I did not find a reply to this question. Has
>>>>> there ever been one? Or does anyone else happen to know the answer to
>>>>> this question? Thank you very much in advance.
>>>>>
>>>>> Yours sincerely,
>>>>>
>>>>> Jaap Buurman
>>>>>
>>>>> August, 2016 message:
>>>>>
>>>>>
>>>>> Hi all,
>>>>>
>>>>> in the MT7621 ethernet driver code
>>>>> (drivers/net/ethernet/mediatek/soc_mt7621.c) the FE_FLAG_JUMBO_FRAME
>>>>> flag is not during the device initialization. This prevents the user
>>>>> to set an MTU greater than 1500. Is this correct? Does MT7621 support
>>>>> jumbo frames?
>>>>>
>>>>> Thanks.
>>>>>
>>>>
>>>> _______________________________________________
>>>> Lede-dev mailing list
>>>> Lede-dev at lists.infradead.org
>>>> http://lists.infradead.org/mailman/listinfo/lede-dev
>
>
>
> --
> gaetano catalli